Elasmobranchi (squali e razze) (sharks and rays) >
Pristiophoriformes (Saw sharks) >
Pristiophoridae (Saw sharks)
Etymology: Pliotrema: pleion (Gr.), more; trema (Gr.), hole, referring to six gill slits compared with five in Pristiophorus (See ETYFish); kajae: In honor of Kaja Magdalena Weigmann, the senior author’s daughter, “who had her first contact with chondrichthyan taxonomy when observing with great interest the examination of Pliotrema specimens for the present study”; “Kaja” is also Frisian (Germanic ethnic group from coastal Netherlands and northwest Germany) for “warrior,” referring to the shark’s saw-like rostrum (See ETYFish).
Eponymy: Kaja Magdalena Weigmann (d: 2015) is the daughter of the first author. [...] (Ref. 128868), visit book page.
Ambiente: milieu / zona climatica / distribuzione batimetrica / gamma di distribuzione
Ecologia
marino demersale; distribuzione batimetrica 214 - 320 m (Ref. 122027). Tropical
Western Indian Ocean: off Madagascar and the Mascarene Ridge.
Dimensione / Peso / Età
Maturità: Lm ?  range ? - ? cm
Max length : 102 cm TL maschio/sesso non determinato; (Ref. 122027); 143.0 cm TL (female)
Breve descrizione
Chiavi di identificazione | Morfologia | Morfometria
This species is distinguished by the following characters: barbel origin to anterior nostrils 1.4-2.3 times anterior nostrils to symphysis upper jaw; prenarial length 1.5-1.7 times prebarbel length; preoral length 2.0-2.7 times interdorsal space; pectoral-fin anterior margin 1.2-1.6 times dorsal-caudal space; mouth width 2.8-6.6 times spiracle length; first dorsal fin originates about opposite pectoral-fin free rear tips; lateral trunk dermal denticles tricuspidate, rather flat and imbricated; monospondylous centra 52-57; precaudal diplospondylous centra 48-56; total vertebral centra 151-64. Differs from its congeners, most notably, a rostrum that is clearly constricted between barbel origin and nostrils; it has sharp folds in both upper and lower jaw teeth, as well as a posteriorly notched, teardrop-shaped dorsal fenestra of the precerebral fossa; differs further from P. warreni by barbels that are situated about half way from rostral tip to mouth, with prebarbel length about equidistant from barbel origin to symphysis of upper jaw (vs. barbels about two thirds way from rostral tip to mouth, with prebarbel length about twice distance from barbel origin to symphysis of upper jaw), and with two indistinct, yellowish longitudinal stripes on the dorsal surface (vs. one pronounced yellowish longitudinal
stripe); differs further from P. annae in having generally longer snout, more upper and lower jaw tooth rows, higher total large lateral rostral tooth and ventral rostral spine counts, and a pale to light brown dorsal coloration with two indistinct yellowish stripes, uniform white ventral coloration, and posterior fin margins with narrow white edges (vs. uniform medium to dark brown dorsally without longitudinal stripes, white ventrally but with few indistinct dark blotches on belly, posterior fin margins conspicuously white-edged). Colouration: pale to light brown dorsally with two thin yellowish longitudinal stripes; uniform white ventrally; fins with rather indistinct white posterior fin margins; dorsal rostrum surface with two distinct longitudinal dark stripes, with lateral rostral teeth dark-edged (Ref. 122027).
Cross section: angular.
A female specimen (117 cm TL) was found gravid with about six eggs (based on radiographs). The size at birth estimated to be around 35 cm TL and was based on the four near-term embryos of 31.8-32.9 cm TL (Ref. 122027).
Ciclo vitale e comportamento di accoppiamento
Maturità | Riproduzione | Deposizione | Uova | Fecondità | Larve
Weigmann, S., O. Gon, R.H. Leeney, E. Barrowclift, P. Berggren, N. Jiddawi and A.J. Temple, 2020. Revision of the sixgill sawsharks, genus Pliotrema (Chondrichthyes, Pristiophoriformes), with descriptions of two new species and a redescription of P. warreni Regan. PLoS ONE, 15 (3)[0228791]:1-56. (Ref. 122027)
Stato della Lista Rossa IUCN (Ref. 130435: Version 2025-2 (Global))
Minaccia per l'uomo
Harmless
Usi umani
Strumenti
Rapporti speciali
Scarica XML
Fonti Internet
Stime basate su modelli
Indice di diversità filogenetica (Fonte Biblio. 82804) |
PD50 = 0.6270 [Uniqueness, from 0.5 = low to 2.0 = high]. |
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Bayesian length-weight
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a=0.00389 (0.00180 - 0.00842), b=3.12 (2.94 - 3.30), in cm total length, based on all LWR estimates for this body shape (Ref. 93245). |
Livello trofico (Fonte Biblio. 69278) |
4.1 ±0.6 se; based on size and trophs of closest relatives |
Vulnerabilità della pesca (Ref. 59153) |
Moderate to high vulnerability (53 of 100). 🛈 |