Kaja's sixgill sawshark

📖 Overview

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 .

🔬 Taxonomy

🐟 Physical Description

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 .Cross section: angular.

🌀 Behaviour

Behavioural data for Kaja's sixgill sawshark is currently being reviewed.

🦐 Diet

🥚 Reproduction

🌍 Habitat & Distribution

Marine; demersal; depth range 214 - 320 m . Tropical Indian Ocean: off Madagascar and the Mascarene Ridge.

🌿 Ecology

📐 Morphometrics

🌡️ Water Parameters & Tolerance

🛡️ Conservation Assessment

📊 Population Risk & Fisheries

🐠 Related Species

🔍 Similar Species

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