FISHERY BULLETIN: VOL. 85, NO. 3 



Figure 1. 



-Male hair crab. Erimacrus isenbeckii , from eastern Bering Sea. Dorsal view. 



shore of the Alaska Peninsula to the Pribilof Is- 

 lands and St. Matthew Island (Fig. 2). Hair crab 

 are also found along the Aleutian Archipelago 

 from Unimak Island as far west as long. 170°E 

 (west of Attn Island; NMFS unpubl. data). In the 

 western Pacific, hair crab occur along the eastern 

 coast of Korea, the western and eastern coasts of 

 Japan, and southern Sakhalin Island (Rathbun 

 1930; Tanikawa 1971). They are particularly 

 abundant around the island of Hokkaido and 

 along the Kurile Islands to southern Kamchatka, 

 and are common along west Kamchatka to lat. 

 54°40'N (Vinogradov 1947). They are unknown 

 from the western Bering Sea. 



Dall reported hair crab from Kachemak Bay 

 and Cook Inlet, AK (Rathbun 1930). These, how- 

 ever, were probably Telmessus cheiragonus, a 

 similar atelecyclid that commonly occurs in the 

 northern Gulf of Alaska (Calkins 1978), since 

 no verified observations of hair crab have been 

 reported east of Unimak Island despite numer- 

 ous inquiries to commercial fishermen and biol- 

 ogists working in the northern gulf in recent 

 years. 



Sakurai et al. (1972) (Fig. 3, bottom) reported 

 that primiparous (first time breeders') female hair 



crab off Hokkaido mate from December to Febru- 

 ary and multiparous (have bred more than once) 

 females mate from August to November (the lat- 

 ter in deeper waters than the former). According 

 to Sakurai et al., mating occurs immediately after 

 molting when females are in the soft-shell condi- 

 tion. When the female is ready to molt, a male 

 crab grasps her chelipeds and holds on to them 

 until after ecdysis. While the female is still soft, 

 the male inserts his copulatory processes into her 

 genital openings and fills the spermathecae with 

 seminal fluid containing spermatophores. The 

 male then secretes a mucoid, proteinaceous sub- 

 stance from his seminal glands which congeals 

 immediately into hard plugs that firmly close the 

 female's genital apertures. The male may then 

 mate with other receptive females. Primiparous 



Figure 3.— Average molting (top, Abe 1984, see text footnote 

 13) and breeding (bottom, adapted from Sakurai et al. 1972) 

 cycles oi Erimacrus isenheckti (through age 8) offshore of south- 

 eastern Hokkaido. It is uncertain when eggs hatch after the 

 second spawning period. Carapace lengths were measured from 

 the notch between the rostral spines. "C" numbers indicate post- 

 larval instars. 



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