cchoi1022/wikitext-103-v1 · Datasets at Hugging Face

text stringlengths 0 6.86k

si una vez ( english if i once ) is a song recorded by american recording artist selena for her fourth studio album amor prohibido ( 1994 ) it was written by pete astudillo and produced by selena 's brother @@ producer ab quintanilla si una vez is a mariachi fusion song and draws influence from cumbia and latin dance music lyrically selena questions why she ever fell in love with an abusive partner saying she will never repeat her mistakes the lyrics suggest unrequited love and female empowerment
si una vez received positive reviews from music critics who found the song to have showcase the singer 's vocal abilities the broadcast music inc recognized it as the single of the year at the 1996 bmi pop awards many musicians have since recorded the song and released it on their respective albums including mexican mariachi singer alicia villareal american reggaeton performer ivy queen american indie rock band girl in a coma and american salsa singer manny manuel the latter 's version peaked at number one on the united states billboard tropical songs chart and ended 1995 as the fourteenth most successful us tropical song

= = background and composition = =

si una vez was written by selena y los dinos backup dancer and vocalist pete astudillo the song was co @@ written by selena 's brother @@ producer ab quintanilla who along with argentine musician bebu silvetti served as producers keyboardist of the group ricky vela retold in a 2002 interview how the band hired a professional <unk> to record parts of the song si una vez is a spanish @@ language mariachi fusion track with influences of cumbia and latin dance music author deborah paredez called si una vez as having punk music undertones in 2002 ab spoke on how amor prohibido was experimental music @@ heavy and commented on how si una vez was an example of his ideas of keeping the band 's image modern the song makes use of the <unk> guitar under a cumbia beat
si una vez is written in the key of d minor and is played in a moderate groove of 84 beats per minute it incorporates music from several musical instruments including the piano and guitar lyrically selena reminiscences her failed relationship and wonders why she ever fell in love with an abusive partner who betrayed and left her vowing to never allow a man like that back into her life the lyrics suggest unrequited love and female empowerment

= = critical reception and legacy = =

si una vez was named by the latin times as one of the top @@ ten best karaoke songs sung in spanish writing for the latin times maria valdez called the song fun especially when running into your former partner at a karaoke party and found the track to showcases a singer 's vocal abilities texas public radio 's nathan cone said the song resonates best with south texas entertainment weekly contributor david browne commented on selena 's vocals as being full @@ throated warbling and that it recalls lydia mendoza conjunto 's leading lady a new university writer found the recording to have showcase [ the singer 's ] passion with her vocals
selena performed the song on her final performance on march 19 1995 during the calle ocho festival in miami which attracted over 100 @@ 000 fans selena was shot and killed by yolanda saldívar her friend and former manager of the singer 's selena etc clothing boutiques on march 31 1995 selena 's performance of the song during her houston astrodome concert on february 26 1995 was emulated by jennifer lopez as her role as the singer for the 1997 biopic film about selena si una vez is considered by billboard magazine to be one of selena 's signature songs terra named si una vez as one of selena 's most famous works along with her other songs el chico del apartamento 512 amor prohibido and fotos y recuerdos the broadcast music inc ( bmi ) recognized si una vez at the bmi pop music awards as single of the year in 1996

= = covers = =

mexican singer mary <unk> recorded the song for the tribute album mexico recuerda a selena ( 2005 ) mexican mariachi singer alicia villareal performed and recorded si una vez for the live televised tribute concert selena ¡ vive in april 2005 american reggaeton singer ivy queen covered si una vez for her fifth studio album flashback ( 2005 ) she said in an interview how she felt honored to be able to cover one of selena 's songs ivy queen chose to cover si una vez finding it to be identifiable to her and because of the song 's message which the singer stood for jonathan widran of allmusic called her versions a reggaetón @@ ed up twist in 2010 indie rock group girl in a coma recorded a punk cover of si una vez the group decided to record the song because it was their favorite recordings of selena girl in a coma performed the song live during the 2010 tejano music awards as a homage to selena in april 2011 ab ' s band kumbia all @@ starz performed their version of the song during their tour for la vida de un genio ( 2010 ) in bolivia colombian singer kali <unk> performed si una vez at the 2015 sxsw festival vibe magazine found <unk> ' performance to have given them shivers

= = = manny manuel version = = =

american merengue musician manny manuel covered the song on his debut album el rey de corazones ( 1995 ) out of the five singles released from the album si una vez was manuel 's most successful single off of the el rey de corazones album the song debuted at number 29 on the united states billboard hot latin tracks and number three on the us tropical songs chart the following week si una vez rose to numbers 22 and two on the hot latin songs and tropical songs chart respectively on october 14 1995 the track climbed to number 21 on the hot latin songs chart while it fell to number four on the tropical songs chart in its fourth week si una vez jumped to number 18 on the hot latin songs chart while over at the tropical songs chart the song rose to number three despite increased airplay spins si una vez fell to number 20 on the hot latin songs chart on november 11 1995 si una vez peaked at number one on the tropical songs chart for one week <unk> airplay honors that week

= = = = chart performance = = = =


= = credits and personnel = =

all credits were taken from the album 's liner notes


= sicklefin lemon shark =

the sicklefin lemon shark or sharptooth lemon shark ( negaprion acutidens ) is a species of requiem shark belonging to the family carcharhinidae widely distributed in the tropical waters of the indo @@ pacific it is closely related to the better @@ known lemon shark ( n brevirostris ) of the americas the two species are almost identical in appearance both being stout @@ bodied sharks with broad heads two dorsal fins of nearly equal size and a plain yellow @@ tinged coloration as its common name suggests the sicklefin lemon shark differs from its american counterpart in having more falcate ( sickle @@ shaped ) fins this large species grows up to 3 @@ 8 m ( 12 ft ) long it generally inhabits water less than 92 m ( 302 ft ) deep in a variety of habitats from mangrove estuaries to coral reefs
a slow @@ moving predator feeding mainly on bony fishes the sicklefin lemon shark seldom travels long distances and many individuals can be found year @@ round at certain locations like other members of its family this species is viviparous with females giving birth to no more than 13 pups every other year following a gestation period of 10 11 months although they are potentially dangerous to humans and known to respond vigorously to any provocation under normal circumstances sicklefin lemon sharks are cautious and tend to retreat if approached the iucn has assessed this species as vulnerable its low reproductive productivity and rate of movement limits the capacity of depleted stocks to recover off india and southeast asia this species has been severely depleted or extirpated by unregulated exploitation for its meat fins and liver oil

= = taxonomy and phylogeny = =

the sicklefin lemon shark was first described as carcharias acutidens by german naturalist eduard rüppell in the 1837 fische des rothen meeres ( fishes of the red sea ) in 1940 australian ichthyologist gilbert percy whitley moved this species to his newly formed genus negaprion the type specimen designated in 1960 is a 68 @@ cm @@ long individual caught in the red sea off jeddah saudi arabia the specific epithet acutidens is derived from the latin acutus meaning sharp and dens meaning teeth the sicklefin lemon shark may also be referred to as <unk> shark indian lemon shark indo @@ pacific lemon shark or simply lemon shark
based on microsatellite dna evidence the sicklefin lemon shark is thought to have diverged from its sister species n brevirostris 10 14 million years ago when the closure of the tethys sea separated lemon sharks in the indian ocean from those in the atlantic the ancestral lemon shark species may have been n <unk> the fossilized teeth of which occur in both the united states and pakistan morphological and molecular phylogenetic analyses suggest that negaprion is grouped with the whitetip reef shark ( triaenodon ) and the <unk> shark ( <unk> ) in occupying an intermediate position on the carcharhinid evolutionary tree between the most basal genera ( galeocerdo rhizoprionodon and scoliodon ) and the most derived ( carcharhinus and sphyrna )

= = distribution and habitat = =

the range of the sicklefin lemon shark extends from south africa to the red sea ( including mauritius the seychelles and madagascar ) continuing eastward along the coast of the indian subcontinent to southeast asia extending as far north as taiwan and the philippines and as far south as new guinea and northern australia this species is also found around numerous pacific islands including new caledonia palau the marshall islands the solomon islands fiji vanuatu and french polynesia this species likely colonized the central pacific by infrequently hopping from one island to the next significant levels of genetic differentiation between sicklefin lemon sharks in australia and french polynesia 750 km ( 470 mi ) apart suggest that little intermingling occurs between regional subpopulations
an inhabitant of coastal continental and insular shelves the sicklefin lemon shark occurs from the intertidal zone to a depth of 92 m ( 302 ft ) this species favors still murky waters and is most common in bays estuaries and lagoons and over sandy flats and outer reefs sometimes an individual may venture into open water one was filmed in the 1971 documentary blue water white death in the vicinity of a sperm whale ( physeter macrocephalus ) carcass juvenile sicklefin lemon sharks are often found on reef flats or around mangroves in water so shallow that their dorsal fins are exposed in herald bight off western australia a known nursery juvenile sicklefin lemon sharks frequent open areas and mangroves in water under 3 m ( 9 @@ 8 ft ) deep but not areas covered by the seagrass posidonia australis

= = description = =

the sicklefin lemon shark has a robust stocky body and a short broad head the snout is rounded or almost wedge @@ shaped with small nostrils bearing triangular flaps of skin in front the eyes are small with no spiracles short furrows are present at the corners of the mouth thirteen to 16 ( usually 14 ) tooth rows occur on either side of both jaws not including the tiny teeth at the symphysis ( the jaw midline ) the upper teeth have a large cusp rising from a broad base with a notch on each side these teeth become increasingly angled towards the corners of the mouth the lower teeth resemble the upper teeth but are narrower and more erect the teeth of sharks over 1 @@ 4 m ( 4 @@ 6 ft ) long are finely serrated
the fins ( especially the dorsal pectoral and <unk> ) of the sicklefin lemon shark are more falcate ( sickle @@ shaped ) than those of the otherwise very similar american lemon shark the first dorsal fin is positioned closer to the pelvic than the pectoral fins the second dorsal fin nearly equal to the first in size is located over or slightly forward of the anal fin no ridge is seen between the dorsal fins the pectoral fins are long and broad originating below the space between the third and fourth gill slits the anal fin has a strong notch in the rear margin the precaudal pit ( a cavity just forward of the caudal fin ) is oriented longitudinally the large dermal denticles are overlapping and bear three to five horizontal ridges each the coloration is a plain yellowish brown or gray above and lighter below with more yellow on the fins this species attains a maximum known length of 3 @@ 8 m ( 12 ft ) though it typically does not exceed 3 @@ 1 m ( 10 ft )

= = biology and ecology = =

a sluggish species the sicklefin lemon shark is usually seen cruising sedately just above the sea bottom or lying still on it as unlike most requiem sharks it is capable of actively pumping water over its gills however it will approach the surface in pursuit of food this shark seldom undertakes long @@ distance movements a study at aldabra atoll in the seychelles found of the tagged sharks that were later recaptured over 90 were still within 2 km ( 1 @@ 2 mi ) of their initial tagging location another study at moorea in french polynesia found that some of the local sharks were year @@ round residents of the island while others were more transitory and visited only occasionally
over 90 of the sicklefin lemon shark 's diet consists of <unk> and shore @@ dwelling teleosts including herring mullets mackerel silversides needlefish smelt @@ whitings porgies sea catfish triggerfish parrotfish and porcupinefish occasionally they may also take cephalopods and crustaceans and older individuals have been known to consume stingrays and guitarfish this species may be preyed upon by larger sharks known parasites include the tapeworms paraorygmatobothrium <unk> <unk> <unk> phoreiobothrium <unk> and platybothrium <unk> sicklefin lemon sharks have been documented resting on the bottom and eliciting cleanings by bluestreak cleaner wrasses ( labroides dimidiatus ) during which they may open their mouths and stop respiring for as long as 150 seconds to give the wrasses access to their mouths and gills
as with other members of its family the sicklefin lemon shark is viviparous the developing embryos are sustained by a placental connection formed from their depleted yolk sacs females give birth to one to 13 ( usually six to 12 ) pups every other year in shallow nursery areas following a gestation period of 10 11 months unlike in the american lemon shark cant evidence indicates this species is philopatric ( returns to the site of their birth to reproduce ) parturition occurs in october or november at madagascar and aldabra and in january at french polynesia ovulation and mating for nonpregnant females takes place at around the same time the embryos develop a placenta after around four months of gestation when they still possess vestiges of external gills the young are born at a length of 45 80 cm ( 18 31 in ) juvenile sharks grow slowly at a rate of 12 @@ 5 15 @@ 5 cm ( 4 @@ 9 6 @@ 1 in ) per year both sexes attain sexual maturity at a length of 2 @@ 2 2 @@ 4 m ( 7 @@ 2 7 @@ 9 ft )

= = human interactions = =

several apparently unprovoked attacks on humans have been attributed to the sicklefin lemon shark due to its formidable size and teeth it is regarded as potentially dangerous and certainly this species has been known to defend itself quickly and vigorously if touched speared or otherwise provoked or alarmed once agitated this shark can be a persistent adversary in one case a shark forced a swimmer to seek refuge atop a coral head and circled for hours before giving up however observations by divers show that normally this shark is shy and hesitant to approach even when presented with bait often the shark will move away when a diver enters visual range young sharks are reportedly more aggressive and inquisitive than the adults at moorea sicklefin lemon sharks are the main attraction of daily shark @@ feeding ecotourism dives this shark adapts well to captivity and is displayed in public aquariums
the iucn has assessed the sicklefin lemon shark globally as vulnerable it is harvested using anchored and floating gillnets beach nets and longlines the meat is sold fresh or dried and salted for human consumption the fins used for shark fin soup and the liver oil is processed for vitamins the sicklefin lemon shark is highly susceptible to local overfishing due to its slow reproductive rate and limited movements off southeast asia this shark has become scarce under the pressure of expanding unmonitored and unregulated fisheries and has been assessed there as endangered by the iucn widespread habitat degradation including pollution and blast fishing on coral reefs and deforestation in mangroves poses an additional threat to the survival of this species in the region already the sicklefin lemon shark has been extirpated in parts of india and thailand and has not been reported from indonesian markets in recent years despite being historically abundant there off australia the sicklefin lemon shark is taken in only small numbers intentionally and as bycatch and has been listed under least concern


= <unk> flycatcher =

the flammulated flycatcher ( deltarhynchus <unk> ) is a species of bird in the tyrannidae family and is the only species in the monotypic genus deltarhynchus although it is closely related to the birds of the genus myiarchus it is endemic to the dry deciduous forest arid thorn forest and scrubby woodland of mexico s pacific coast the flycatcher is an olive to gray @@ brown bird with a streaked pale gray chest white throat black bill dark gray feet and dark brown wings it is a skulking bird that typically remains hidden in the underbrush it feeds by gleaning insects off of leaves and twigs that it spots from an exposed perch the female lays approximately three eggs in a nest made in a shallow tree cavity

= = taxonomy = =

the species was first described in 1875 by ornithologist george newbold lawrence who placed this species in the genus myiarchus however in 1893 it was split from myiarchus into the new monotypic genus deltarhynchus by robert ridgway because of its shorter and broader bill more rounded wings and partially streaked underparts this change was upheld in 1901 by richard bowdler sharpe and by subsequent authors however in 1977 ornithologist melvin alvah traylor jr while upholding its status as a monotypic genus said that the species should be lumped back into myiarchus if its nesting habits were similar to those of that genus these doubts were put to rest by wesley lanyon 's research of the flycatcher in 1979 which confirmed the bird 's placement in a monotypic genus
deltarhynchus is similar to the genus myiarchus but is distinguished from it by a broader and shorter bill more rounded wings a different face pattern pale cinnamon wing and tail edgings voice streaking on the chest and the bird 's skulking habits the flammulated flycatcher 's generic name is derived from the ancient greek words delta which means delta @@ shaped or in this case wedge and rhynchos which means beak its specific epithet is derived from the latin word <unk> which means little flame the flycatcher has no subspecies

= = description = =

the flammulated flycatcher is approximately 6 to 6 @@ 5 inches ( 15 @@ 16 @@ 5 cm ) in length and has a chunky body adult males and females are similar in plumage with each possessing olive to a worn gray @@ brown upperparts and head a whitish supraloral stripe and crescent are behind the bird 's eyes it also has a dusky lore the throat is whitish and the chest is a pale gray with inconspicuous dusky streaking while the belly and undertail coverts are a pale yellow additionally this species has dark brown well @@ rounded wings with pale cinnamon @@ edged coverts and remiges the wings are about 3 inches ( 76 mm ) long the tail is also a dark brown edged with a narrow band of pale cinnamon it is barely shorter than the wing and slightly rounded the bird 's bill is black broad and triangular with a slightly paler base and about half the length of the its head the legs are a dark gray and end with large curved and sharp claws it has an orange mouth and a brown eye the juvenile is similar to the adult although the tail has a broad band of pale cinnamon

= = = vocalization = = =

the flammulated flycatcher mostly sings from april to august which includes its breeding season and tends to remain hidden while singing the song of the flycatcher is a plaintive whistle followed by a short but quick roll it can also give a plaintive and slurred chew call which is often sung three to five times in a descending series as well as a squeaky chatter calls are the same for males and females and are given throughout the day to give a location identify an individual sound an alarm and mark the limits of a territory among other functions during the breeding season males give what is known as a dawn song every morning which includes the calls chee @@ bee beet and churr @@ r @@ r @@ bee bee in alternation

= = distribution and habitat = =

this flycatcher is endemic to the pacific lowlands of mexico 's western coast from sinaloa to western chiapas while possibly extending into guatemala although this has not been confirmed the total area that it lives in is estimated to be 66 @@ 000 km2 ( 25 @@ 482 @@ 7 sq mi ) its range is discontinuous and it is found in low densities when present it lives in dry deciduous forest arid and semi @@ arid thorn forest and scrubby woodland at about 1000 1400 meters ( <unk> <unk> ft ) above sea level this species is non @@ migratory

= = = status = = =

the flammulated flycatcher is listed as being of least concern on the iucn red list due to its large range and the belief that the total population numbers over 10 @@ 000 individuals however no precise estimate on the bird 's population exists while the species is known to be uncommon in parts of its range its population is not believed to be declining enough to pass the threshold of 30 in ten years or three generations necessary to be listed as near threatened although the exact population trends also have not been quantified

= = ecology and behavior = =

this flycatcher is a sluggish and skulking species that usually remains in the underbrush when excited either by an intruder or when attempting to attract a mate this species raises the feathers on its crown to form what appears to be a crest however unlike the closely related genus myiarchus it does not bob its head while displaying the crest

= = = feeding = = =

the flammulated flycatcher forages by perching on an open branch and looking outward and downward for prey which primarily consists of insects once it spots a potential meal the flycatcher rapidly and directly flies at the insect which is normally on the exposed upper surface of a leaf or twig it hovers briefly before the insect before grabbing it in its beak and flying away to typically a new perch

= = = reproduction = = =

the flycatcher breeds around june of each year it nests in shallow tree cavities that are surprisingly close to the ground at approximately 90 centimeters above it the nest is shaped like a cup and is composed of fine vegetable fibers dried leaves and shredded bark unlike the similar myiarchus flycatchers it does not use snakeskin or other materials to build its nest the female lays three eggs that are creamy to pinkish in color and are decorated with brown and gray splotches

si una vez ( english if i once ) is a song recorded by american recording artist selena for her fourth studio album amor prohibido ( 1994 ) it was written by pete astudillo and produced by selena 's brother @@ producer ab quintanilla si una vez is a mariachi fusion song and draws influence from cumbia and latin dance music lyrically selena questions why she ever fell in love with an abusive partner saying she will never repeat her mistakes the lyrics suggest unrequited love and female empowerment

si una vez received positive reviews from music critics who found the song to have showcase the singer 's vocal abilities the broadcast music inc recognized it as the single of the year at the 1996 bmi pop awards many musicians have since recorded the song and released it on their respective albums including mexican mariachi singer alicia villareal american reggaeton performer ivy queen american indie rock band girl in a coma and american salsa singer manny manuel the latter 's version peaked at number one on the united states billboard tropical songs chart and ended 1995 as the fourteenth most successful us tropical song

= = background and composition = =

si una vez was written by selena y los dinos backup dancer and vocalist pete astudillo the song was co @@ written by selena 's brother @@ producer ab quintanilla who along with argentine musician bebu silvetti served as producers keyboardist of the group ricky vela retold in a 2002 interview how the band hired a professional <unk> to record parts of the song si una vez is a spanish @@ language mariachi fusion track with influences of cumbia and latin dance music author deborah paredez called si una vez as having punk music undertones in 2002 ab spoke on how amor prohibido was experimental music @@ heavy and commented on how si una vez was an example of his ideas of keeping the band 's image modern the song makes use of the <unk> guitar under a cumbia beat

si una vez is written in the key of d minor and is played in a moderate groove of 84 beats per minute it incorporates music from several musical instruments including the piano and guitar lyrically selena reminiscences her failed relationship and wonders why she ever fell in love with an abusive partner who betrayed and left her vowing to never allow a man like that back into her life the lyrics suggest unrequited love and female empowerment

= = critical reception and legacy = =

si una vez was named by the latin times as one of the top @@ ten best karaoke songs sung in spanish writing for the latin times maria valdez called the song fun especially when running into your former partner at a karaoke party and found the track to showcases a singer 's vocal abilities texas public radio 's nathan cone said the song resonates best with south texas entertainment weekly contributor david browne commented on selena 's vocals as being full @@ throated warbling and that it recalls lydia mendoza conjunto 's leading lady a new university writer found the recording to have showcase [ the singer 's ] passion with her vocals

selena performed the song on her final performance on march 19 1995 during the calle ocho festival in miami which attracted over 100 @@ 000 fans selena was shot and killed by yolanda saldívar her friend and former manager of the singer 's selena etc clothing boutiques on march 31 1995 selena 's performance of the song during her houston astrodome concert on february 26 1995 was emulated by jennifer lopez as her role as the singer for the 1997 biopic film about selena si una vez is considered by billboard magazine to be one of selena 's signature songs terra named si una vez as one of selena 's most famous works along with her other songs el chico del apartamento 512 amor prohibido and fotos y recuerdos the broadcast music inc ( bmi ) recognized si una vez at the bmi pop music awards as single of the year in 1996

= = covers = =

mexican singer mary <unk> recorded the song for the tribute album mexico recuerda a selena ( 2005 ) mexican mariachi singer alicia villareal performed and recorded si una vez for the live televised tribute concert selena ¡ vive in april 2005 american reggaeton singer ivy queen covered si una vez for her fifth studio album flashback ( 2005 ) she said in an interview how she felt honored to be able to cover one of selena 's songs ivy queen chose to cover si una vez finding it to be identifiable to her and because of the song 's message which the singer stood for jonathan widran of allmusic called her versions a reggaetón @@ ed up twist in 2010 indie rock group girl in a coma recorded a punk cover of si una vez the group decided to record the song because it was their favorite recordings of selena girl in a coma performed the song live during the 2010 tejano music awards as a homage to selena in april 2011 ab ' s band kumbia all @@ starz performed their version of the song during their tour for la vida de un genio ( 2010 ) in bolivia colombian singer kali <unk> performed si una vez at the 2015 sxsw festival vibe magazine found <unk> ' performance to have given them shivers

= = = manny manuel version = = =

american merengue musician manny manuel covered the song on his debut album el rey de corazones ( 1995 ) out of the five singles released from the album si una vez was manuel 's most successful single off of the el rey de corazones album the song debuted at number 29 on the united states billboard hot latin tracks and number three on the us tropical songs chart the following week si una vez rose to numbers 22 and two on the hot latin songs and tropical songs chart respectively on october 14 1995 the track climbed to number 21 on the hot latin songs chart while it fell to number four on the tropical songs chart in its fourth week si una vez jumped to number 18 on the hot latin songs chart while over at the tropical songs chart the song rose to number three despite increased airplay spins si una vez fell to number 20 on the hot latin songs chart on november 11 1995 si una vez peaked at number one on the tropical songs chart for one week <unk> airplay honors that week

= = = = chart performance = = = =

= = credits and personnel = =

all credits were taken from the album 's liner notes

= sicklefin lemon shark =

the sicklefin lemon shark or sharptooth lemon shark ( negaprion acutidens ) is a species of requiem shark belonging to the family carcharhinidae widely distributed in the tropical waters of the indo @@ pacific it is closely related to the better @@ known lemon shark ( n brevirostris ) of the americas the two species are almost identical in appearance both being stout @@ bodied sharks with broad heads two dorsal fins of nearly equal size and a plain yellow @@ tinged coloration as its common name suggests the sicklefin lemon shark differs from its american counterpart in having more falcate ( sickle @@ shaped ) fins this large species grows up to 3 @@ 8 m ( 12 ft ) long it generally inhabits water less than 92 m ( 302 ft ) deep in a variety of habitats from mangrove estuaries to coral reefs

a slow @@ moving predator feeding mainly on bony fishes the sicklefin lemon shark seldom travels long distances and many individuals can be found year @@ round at certain locations like other members of its family this species is viviparous with females giving birth to no more than 13 pups every other year following a gestation period of 10 11 months although they are potentially dangerous to humans and known to respond vigorously to any provocation under normal circumstances sicklefin lemon sharks are cautious and tend to retreat if approached the iucn has assessed this species as vulnerable its low reproductive productivity and rate of movement limits the capacity of depleted stocks to recover off india and southeast asia this species has been severely depleted or extirpated by unregulated exploitation for its meat fins and liver oil

= = taxonomy and phylogeny = =

the sicklefin lemon shark was first described as carcharias acutidens by german naturalist eduard rüppell in the 1837 fische des rothen meeres ( fishes of the red sea ) in 1940 australian ichthyologist gilbert percy whitley moved this species to his newly formed genus negaprion the type specimen designated in 1960 is a 68 @@ cm @@ long individual caught in the red sea off jeddah saudi arabia the specific epithet acutidens is derived from the latin acutus meaning sharp and dens meaning teeth the sicklefin lemon shark may also be referred to as <unk> shark indian lemon shark indo @@ pacific lemon shark or simply lemon shark

based on microsatellite dna evidence the sicklefin lemon shark is thought to have diverged from its sister species n brevirostris 10 14 million years ago when the closure of the tethys sea separated lemon sharks in the indian ocean from those in the atlantic the ancestral lemon shark species may have been n <unk> the fossilized teeth of which occur in both the united states and pakistan morphological and molecular phylogenetic analyses suggest that negaprion is grouped with the whitetip reef shark ( triaenodon ) and the <unk> shark ( <unk> ) in occupying an intermediate position on the carcharhinid evolutionary tree between the most basal genera ( galeocerdo rhizoprionodon and scoliodon ) and the most derived ( carcharhinus and sphyrna )

= = distribution and habitat = =

the range of the sicklefin lemon shark extends from south africa to the red sea ( including mauritius the seychelles and madagascar ) continuing eastward along the coast of the indian subcontinent to southeast asia extending as far north as taiwan and the philippines and as far south as new guinea and northern australia this species is also found around numerous pacific islands including new caledonia palau the marshall islands the solomon islands fiji vanuatu and french polynesia this species likely colonized the central pacific by infrequently hopping from one island to the next significant levels of genetic differentiation between sicklefin lemon sharks in australia and french polynesia 750 km ( 470 mi ) apart suggest that little intermingling occurs between regional subpopulations

an inhabitant of coastal continental and insular shelves the sicklefin lemon shark occurs from the intertidal zone to a depth of 92 m ( 302 ft ) this species favors still murky waters and is most common in bays estuaries and lagoons and over sandy flats and outer reefs sometimes an individual may venture into open water one was filmed in the 1971 documentary blue water white death in the vicinity of a sperm whale ( physeter macrocephalus ) carcass juvenile sicklefin lemon sharks are often found on reef flats or around mangroves in water so shallow that their dorsal fins are exposed in herald bight off western australia a known nursery juvenile sicklefin lemon sharks frequent open areas and mangroves in water under 3 m ( 9 @@ 8 ft ) deep but not areas covered by the seagrass posidonia australis

= = description = =

the sicklefin lemon shark has a robust stocky body and a short broad head the snout is rounded or almost wedge @@ shaped with small nostrils bearing triangular flaps of skin in front the eyes are small with no spiracles short furrows are present at the corners of the mouth thirteen to 16 ( usually 14 ) tooth rows occur on either side of both jaws not including the tiny teeth at the symphysis ( the jaw midline ) the upper teeth have a large cusp rising from a broad base with a notch on each side these teeth become increasingly angled towards the corners of the mouth the lower teeth resemble the upper teeth but are narrower and more erect the teeth of sharks over 1 @@ 4 m ( 4 @@ 6 ft ) long are finely serrated

the fins ( especially the dorsal pectoral and <unk> ) of the sicklefin lemon shark are more falcate ( sickle @@ shaped ) than those of the otherwise very similar american lemon shark the first dorsal fin is positioned closer to the pelvic than the pectoral fins the second dorsal fin nearly equal to the first in size is located over or slightly forward of the anal fin no ridge is seen between the dorsal fins the pectoral fins are long and broad originating below the space between the third and fourth gill slits the anal fin has a strong notch in the rear margin the precaudal pit ( a cavity just forward of the caudal fin ) is oriented longitudinally the large dermal denticles are overlapping and bear three to five horizontal ridges each the coloration is a plain yellowish brown or gray above and lighter below with more yellow on the fins this species attains a maximum known length of 3 @@ 8 m ( 12 ft ) though it typically does not exceed 3 @@ 1 m ( 10 ft )

= = biology and ecology = =

a sluggish species the sicklefin lemon shark is usually seen cruising sedately just above the sea bottom or lying still on it as unlike most requiem sharks it is capable of actively pumping water over its gills however it will approach the surface in pursuit of food this shark seldom undertakes long @@ distance movements a study at aldabra atoll in the seychelles found of the tagged sharks that were later recaptured over 90 were still within 2 km ( 1 @@ 2 mi ) of their initial tagging location another study at moorea in french polynesia found that some of the local sharks were year @@ round residents of the island while others were more transitory and visited only occasionally

over 90 of the sicklefin lemon shark 's diet consists of <unk> and shore @@ dwelling teleosts including herring mullets mackerel silversides needlefish smelt @@ whitings porgies sea catfish triggerfish parrotfish and porcupinefish occasionally they may also take cephalopods and crustaceans and older individuals have been known to consume stingrays and guitarfish this species may be preyed upon by larger sharks known parasites include the tapeworms paraorygmatobothrium <unk> <unk> <unk> phoreiobothrium <unk> and platybothrium <unk> sicklefin lemon sharks have been documented resting on the bottom and eliciting cleanings by bluestreak cleaner wrasses ( labroides dimidiatus ) during which they may open their mouths and stop respiring for as long as 150 seconds to give the wrasses access to their mouths and gills

as with other members of its family the sicklefin lemon shark is viviparous the developing embryos are sustained by a placental connection formed from their depleted yolk sacs females give birth to one to 13 ( usually six to 12 ) pups every other year in shallow nursery areas following a gestation period of 10 11 months unlike in the american lemon shark cant evidence indicates this species is philopatric ( returns to the site of their birth to reproduce ) parturition occurs in october or november at madagascar and aldabra and in january at french polynesia ovulation and mating for nonpregnant females takes place at around the same time the embryos develop a placenta after around four months of gestation when they still possess vestiges of external gills the young are born at a length of 45 80 cm ( 18 31 in ) juvenile sharks grow slowly at a rate of 12 @@ 5 15 @@ 5 cm ( 4 @@ 9 6 @@ 1 in ) per year both sexes attain sexual maturity at a length of 2 @@ 2 2 @@ 4 m ( 7 @@ 2 7 @@ 9 ft )

= = human interactions = =

several apparently unprovoked attacks on humans have been attributed to the sicklefin lemon shark due to its formidable size and teeth it is regarded as potentially dangerous and certainly this species has been known to defend itself quickly and vigorously if touched speared or otherwise provoked or alarmed once agitated this shark can be a persistent adversary in one case a shark forced a swimmer to seek refuge atop a coral head and circled for hours before giving up however observations by divers show that normally this shark is shy and hesitant to approach even when presented with bait often the shark will move away when a diver enters visual range young sharks are reportedly more aggressive and inquisitive than the adults at moorea sicklefin lemon sharks are the main attraction of daily shark @@ feeding ecotourism dives this shark adapts well to captivity and is displayed in public aquariums

the iucn has assessed the sicklefin lemon shark globally as vulnerable it is harvested using anchored and floating gillnets beach nets and longlines the meat is sold fresh or dried and salted for human consumption the fins used for shark fin soup and the liver oil is processed for vitamins the sicklefin lemon shark is highly susceptible to local overfishing due to its slow reproductive rate and limited movements off southeast asia this shark has become scarce under the pressure of expanding unmonitored and unregulated fisheries and has been assessed there as endangered by the iucn widespread habitat degradation including pollution and blast fishing on coral reefs and deforestation in mangroves poses an additional threat to the survival of this species in the region already the sicklefin lemon shark has been extirpated in parts of india and thailand and has not been reported from indonesian markets in recent years despite being historically abundant there off australia the sicklefin lemon shark is taken in only small numbers intentionally and as bycatch and has been listed under least concern

= <unk> flycatcher =

the flammulated flycatcher ( deltarhynchus <unk> ) is a species of bird in the tyrannidae family and is the only species in the monotypic genus deltarhynchus although it is closely related to the birds of the genus myiarchus it is endemic to the dry deciduous forest arid thorn forest and scrubby woodland of mexico s pacific coast the flycatcher is an olive to gray @@ brown bird with a streaked pale gray chest white throat black bill dark gray feet and dark brown wings it is a skulking bird that typically remains hidden in the underbrush it feeds by gleaning insects off of leaves and twigs that it spots from an exposed perch the female lays approximately three eggs in a nest made in a shallow tree cavity

= = taxonomy = =

the species was first described in 1875 by ornithologist george newbold lawrence who placed this species in the genus myiarchus however in 1893 it was split from myiarchus into the new monotypic genus deltarhynchus by robert ridgway because of its shorter and broader bill more rounded wings and partially streaked underparts this change was upheld in 1901 by richard bowdler sharpe and by subsequent authors however in 1977 ornithologist melvin alvah traylor jr while upholding its status as a monotypic genus said that the species should be lumped back into myiarchus if its nesting habits were similar to those of that genus these doubts were put to rest by wesley lanyon 's research of the flycatcher in 1979 which confirmed the bird 's placement in a monotypic genus

deltarhynchus is similar to the genus myiarchus but is distinguished from it by a broader and shorter bill more rounded wings a different face pattern pale cinnamon wing and tail edgings voice streaking on the chest and the bird 's skulking habits the flammulated flycatcher 's generic name is derived from the ancient greek words delta which means delta @@ shaped or in this case wedge and rhynchos which means beak its specific epithet is derived from the latin word <unk> which means little flame the flycatcher has no subspecies

= = description = =

the flammulated flycatcher is approximately 6 to 6 @@ 5 inches ( 15 @@ 16 @@ 5 cm ) in length and has a chunky body adult males and females are similar in plumage with each possessing olive to a worn gray @@ brown upperparts and head a whitish supraloral stripe and crescent are behind the bird 's eyes it also has a dusky lore the throat is whitish and the chest is a pale gray with inconspicuous dusky streaking while the belly and undertail coverts are a pale yellow additionally this species has dark brown well @@ rounded wings with pale cinnamon @@ edged coverts and remiges the wings are about 3 inches ( 76 mm ) long the tail is also a dark brown edged with a narrow band of pale cinnamon it is barely shorter than the wing and slightly rounded the bird 's bill is black broad and triangular with a slightly paler base and about half the length of the its head the legs are a dark gray and end with large curved and sharp claws it has an orange mouth and a brown eye the juvenile is similar to the adult although the tail has a broad band of pale cinnamon

= = = vocalization = = =

the flammulated flycatcher mostly sings from april to august which includes its breeding season and tends to remain hidden while singing the song of the flycatcher is a plaintive whistle followed by a short but quick roll it can also give a plaintive and slurred chew call which is often sung three to five times in a descending series as well as a squeaky chatter calls are the same for males and females and are given throughout the day to give a location identify an individual sound an alarm and mark the limits of a territory among other functions during the breeding season males give what is known as a dawn song every morning which includes the calls chee @@ bee beet and churr @@ r @@ r @@ bee bee in alternation

= = distribution and habitat = =

this flycatcher is endemic to the pacific lowlands of mexico 's western coast from sinaloa to western chiapas while possibly extending into guatemala although this has not been confirmed the total area that it lives in is estimated to be 66 @@ 000 km2 ( 25 @@ 482 @@ 7 sq mi ) its range is discontinuous and it is found in low densities when present it lives in dry deciduous forest arid and semi @@ arid thorn forest and scrubby woodland at about 1000 1400 meters ( <unk> <unk> ft ) above sea level this species is non @@ migratory

= = = status = = =

the flammulated flycatcher is listed as being of least concern on the iucn red list due to its large range and the belief that the total population numbers over 10 @@ 000 individuals however no precise estimate on the bird 's population exists while the species is known to be uncommon in parts of its range its population is not believed to be declining enough to pass the threshold of 30 in ten years or three generations necessary to be listed as near threatened although the exact population trends also have not been quantified

= = ecology and behavior = =

this flycatcher is a sluggish and skulking species that usually remains in the underbrush when excited either by an intruder or when attempting to attract a mate this species raises the feathers on its crown to form what appears to be a crest however unlike the closely related genus myiarchus it does not bob its head while displaying the crest

= = = feeding = = =

the flammulated flycatcher forages by perching on an open branch and looking outward and downward for prey which primarily consists of insects once it spots a potential meal the flycatcher rapidly and directly flies at the insect which is normally on the exposed upper surface of a leaf or twig it hovers briefly before the insect before grabbing it in its beak and flying away to typically a new perch

= = = reproduction = = =

the flycatcher breeds around june of each year it nests in shallow tree cavities that are surprisingly close to the ground at approximately 90 centimeters above it the nest is shaped like a cup and is composed of fine vegetable fibers dried leaves and shredded bark unlike the similar myiarchus flycatchers it does not use snakeskin or other materials to build its nest the female lays three eggs that are creamy to pinkish in color and are decorated with brown and gray splotches