ইলাসমোব্রাঙ্কি (হাঙ্গর এবং রে) (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).
Environment: milieu / climate zone / depth range / distribution range
বাস্তুসংস্থান
সামুদ্রিক তলদেশ বিহারী; গভীরতার পরিসীমা 214 - 320 m (Ref. 122027). Tropical
Western Indian Ocean: off Madagascar and the Mascarene Ridge.
আকৃতি / ওজন / Age
Maturity: Lm ? range ? - ? cm
Max length : 102 cm TL পুরুষ/ লিঙ্গ অনিধর্ারিত ; (Ref. 122027); 143.0 cm TL (female)
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).
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).
Life cycle and mating behavior
পরিপক্কতা | প্রজনন | ডিম ছাড়া | ডিমসমূহ | ডিম্বধারন ক্ষমতা | শুককীট
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)
IUCN Red List Status (Ref. 130435)
Threat to humans
Harmless
Human uses
আরো তথ্য
প্রচলিত নাম সমূহপ্রতিনাম সমূহবিপাকশিকারী প্রাণী সমূহপরিবেশ বিষাক্ততাবিদ্যাপ্রজনন পরিপক্কতা ডিম ছাড়া ডিমের সংগ্রহ ডিম্বধারন ক্ষমতা ডিমসমূহEgg development
Age/Sizeবৃদ্ধিLength-weightLength-lengthLength-frequenciesমরফোমেট্রিক্সবহিঃ অঙ্গ সংস্থানশুককীট শুককীটের সত্রিুয়তা নির্বাচন প্রাচুর্য BRUVS
সূত্র সংখ্যা এ্যাকুয়াকালচার (জলজ পালন) এ্যাকুয়াকালচার নকশা বংশ বংশানুগতিবিদ্যাElectrophoresesউতরাধিকার সুত্রে পাওয়া যোগ্যতারোগ প্রক্রিয়াজাতকরণ NutrientsMass conversion
সহযোগী ছবি সমূহStamps, Coins Misc.শব্দ ক্রোমোজোমের ধরণ গতি সাতাঁরের কায়দা ফুলকা এলাকাOtolithsমস্তিস্ক সমূহদৃষ্টি
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ইন্টারনেট সুত্র
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = No PD50 data [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: 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).
ট্রফিক পর্যায়ে (Ref.
69278): 4.1 ±0.6 se; based on size and trophs of closest relatives
Fishing Vulnerability (Ref.
59153): Very high vulnerability (86 of 100).
