مارماهيان دهان گرد (hagfishes) >
Myxiniformes (Hagfishes) >
Myxinidae (Hagfishes) > Eptatretinae
Etymology: Eptatretus: hepta (Gr.), seven; tretos (Gr.), perforated (i.e., with holes), referring to seven gill apertures on what would later be described as Homea banksii (=E. cirrhatus) [range within genus is 6-14 pairs of gill apertures]. (See ETYFish); nelsoni: In honor of ichthyologist Gareth J. Nelson (b. 1937), then with the American Museum of Natural History, for contributions to the promotion of phylogenetic systematics. (See ETYFish).
Environment: milieu / climate zone / depth range / distribution range
بوم شناسي
دريايي نزديك كف زي; غير مهاجر; تغييرات عمق 50 - 250 m (Ref. 51420). Subtropical
Northwest Pacific: southwest Taiwan.
Length at first maturity / Size / Weight / سن
Maturity: Lm 24.0, range 22 - 26 cm
Max length : 25.9 cm TL جنس نر / بدون خواص جنسي; (Ref. 51420)
Gill apertures usually 5 (4-6). Slime pores: prebranchial 14-20; branchial 0; trunk 35-39; tail 6-10; total 57-67. Gill apertures nonlinear and crowded.
A dwarf species; males develop testes at about 20 cm and a 22.4 cm female had elongated eggs; a 26.8 cm specimen had eggs 2.4 cm long; and a 24.4 cm specimen had 11 eggs about 1.5 cm long with polar caps already forming (Ref. 51420).
Life cycle and mating behavior
Maturities | تولید مثل | Spawnings | Egg(s) | Fecundities | توزاد ( لارو)
Copulatory organ absent. The gonads of hagfishes are situated in the peritoneal cavity. The ovary is found in the anterior portion of the gonad, and the testis is found in the posterior part. The animal becomes female if the cranial part of the gonad develops or male if the caudal part undergoes differentiation. If none develops, then the animal becomes sterile. If both anterior and posterior parts develop, then the animal becomes a functional hermaphrodite. However, hermaphroditism being characterised as functional needs to be validated by more reproduction studies (Ref. 51361 ).
Fernholm, B., 1998. Hagfish systematics. p. 33-44. In J.M. Jørgensen, J.P. Lomholt, R.E. Weber and H. Malte (eds.) The biology of hagfishes. Chapman & Hall, London. 578 p. (Ref. 31276)
وضعيت در فهرست قرمز IUCN (Ref. 130435)
خطر برای انسان ها
Harmless
استفاده انسانی
ابزارها
گزارش های ويژه
بارگيری XML
منابع اينترنتي
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00204 (0.00092 - 0.00452), b=2.93 (2.73 - 3.13), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.9 ±0.7 se; based on size and trophs of closest relatives
جهندگی (Ref.
120179): پايين ، كم, كمينه زمان لازم براي دو برابر شدن جمعيت 5/4 – 14 سال (Fec assumed to be <100).
Fishing Vulnerability (Ref.
59153): Low vulnerability (16 of 100).
