4 resultados para Torpediniformes


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Benthobatis kreffti n. sp. is described as the third species of this genus of blind deep-water electric rays, based on 150 specimens taken from the continental slope off South Brazil. The new species is the smallest within the genus (TL less than 300 mm) and is compared with both congeners, B. marcida from the north-western Atlantic and B. moresbyi from the northern Indian Ocean. B. kreffti is characterised beyond its small size mainly by plain dark colouration dorsally and a white underside, with dark margins of disc and pelvics, as well as by totally degenerated eyes almost no longer visible externally. The new species is diagnosed further by very low tooth counts of 9 to 13 rows and lack of folds, keels or ridges on sides of tail.

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A new species of electric ray of the family Narcinidae, Discopyge castelloi, is described from the southwestern Atlantic off Argentina. Distinctive characters of the new species are the form of the body, the posterior position of pelvic fins and the manner as pelvic fins join the caudal peduncle, the morphology of the nasal curtain and the presence of small but apparently functional eyes. Discopyge castelloi is the fourth torpediniform species reported from the area. It appears to be very rare on the shelf, though the type locality is separated from that of the paratypes by seven latitude degrees. As in the case of Torpedo puelcha, it is probable that the new species has a normal habitat deeper than that of the available specimens.

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This study provides information on the reproductive biology of Narcine brasiliensis based on 105 individuals (72 females and 33 males) sampled in São Paulo State, Brazil. The total length at maturity for females was 318·9 mm and for males was 279·8 mm; pregnant females were observed only during summer and autumn. The peak of the gonado-somatic index for females and condition factor for males in the spring suggest a preparation for pregnancy and a mating period during this season. The capture of immature individuals indicates a need for management of the species in this region.

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O afloramento de Brielas, costa de Caparica (Miocénico Médio) apresenta uma elevada riqueza especifica representada neste estudo por 671 dentes isolados, 11 dentículos dérmicos e 4 fragmentos de aguilhão. Foram identificados e descritos quarenta seis taxa pertencentes as seguintes ordens: Carcharhiniformes,Myliobatiformes, Hexanchiformes, Lamniformes, Rajiformes, Squatiniformes e Torpediniformes. Trata-se de uma fauna cuja maioria dos géneros possuem representantes actuais e onde se encontram, inclusivamente,algumas espécies que existem actualmente no território marítimo português. Descreve-se pela primeira vez no registo f6ssil português Torpedo torpedo, e o género Mustelus é descrito em idade mais antiga que a da primeira referencia deste género em Portugal. Verifica-se a presença de formas bentónicas e nectónicas de águas quentes tropicais a temperadas, que habitariam frequentemente zonas costeiras; é de notar a presença de certas formas em detrimento de outras, reforçando as conclusões de investigadores anteriores.