FISHERY BULLETIN: VOL. 79, NO. 1 



Table 2. — Measurements (millimeters) of selected body parts 

 of larvae o{ Embassichthys bathybius. 



ventral body margins than laterally. Pigment also 

 occurs on the finfold in the region of the bands, 

 particularly at the finfold margins near the an- 

 terior two bands. During development, the most 

 distinctive pigment additions occur along the fin 

 fold (fin) margins, vi^ith seven patches forming 

 along the dorsal fin and five along the ventral fin of 

 the largest specimen. Pigment patches are also 

 added to the dorsal and ventral body margins, 

 generally in the vicinity of the fin fold (fin) 

 patches, initially between the anterior two tail 

 bands. With grovd;h the original pigment bands 

 become discontinuous laterally except for the one 

 at the tail tip which eventually appears as a patch 

 on the caudal peduncle. Some pigment is also 

 added ventrally in the abdominal region. 



Initially the larvae are relatively long and slen- 

 der with body depth at the anus 7% SL in the 

 smallest larvae and 13% SL by 15.4 mm. Body 

 depth increases considerably by 16.2 mm when it 

 is 35% SL at the anus. Snout to anus distance is 

 31-34% SL until 16.2 mm when it increases to 40% 

 SL. Between 15.4 and 16.2 mm a number of events 

 occur including notochord flexion; dorsal, anal, 

 and caudal fin development; and formation of pel- 

 vic fin buds. By 16.2 mm, the adult complement of 

 dorsal (109-117) and anal (94-98) fin rays (Miller 

 and Lea 1972) is attained but the caudal fin rays 

 are not fully developed, based on the incomplete 

 count of 8 + 8, and pectoral fin rays are not yet 

 formed. No head or body spines are apparent on 

 any of the larvae. 



COMPARISON 



The only other pleuronectids occurring in the 

 northeast Pacific with >60 vertebrae are 

 Reinhardtius hippoglossoides and Glyptocephalus 

 zachirus (Norman 1934; Miller and Lea 1972; Hart 

 1973). Eggs of i?. hippoglossoides are 4.0-4.5 mm 

 in diameter (Pertseva-Ostroumova 1961) and 

 those of G. zachirus are 1.98-2.34 mm (Pearcy et 

 al. 1977) compared with about 3.0 mm for E. 



bathybius. Larvae of R. hippoglossoides are 

 lightly pigmented with melanophores lining the 

 myosepta but never appearing as pronounced 

 pigment bands on the body (Pertseva-Ostroumova 

 1961; Nichols 1971) as in E. bathybius. Small (< 11 

 mm) larvae of G. zachirus have four postanal pig- 

 ment bands (Ahlstrom and Moser 1975) compared 

 with three in E. bathybius. The bands in G. 

 zachirus extend with uniform intensity from dor- 

 sal to ventral body margins whereas those in E. 

 bathybius are concentrated along the dorsal and 

 ventral margins and are less intense laterally. 

 With development these bands persist laterally in 

 G. zachirus while the anterior two bands persist 

 only near the body margins in E. bathybius. Small 

 (<11 mm) larvae of G. zachirus also have a 

 relatively shorter snout to anus distance 

 (range = 25.3-27.2% SL; mean = 26.2% SL 

 based on four specimens) than E. bathybius 

 (range = 30.8-32.7% SL; mean = 31.8% SL 

 based on two specimens). Freshly preserved larvae 

 of E. bathybius possess scattered orange 

 chromatophores on the body whereas larvae of G. 

 zachirus have none. Eye migration begins at a 

 smaller size in E. bathybius (at least by 16.2 mm) 

 than in G. zachirus [34-35 mm (Pearcy et al. 1977)] 

 indicating that final transformation to juvenile 

 may take place at a smaller size in E. bathybius 

 compared with 45 mm or larger (Pearcy et al. 1977) 

 for G. zachirus. 



OCCURRENCE 



Because of the paucity of specimens of E. 

 bathybius little can be said about temporal and 

 spatial distribution. All were collected between 

 March and June (Table 1) which may indicate a 

 winter-spring spawning period similar to that of 

 many species off Oregon (Pearcy et al. 1977; 

 Richardson and Pearcy 1977). Additional docu- 

 mentation is needed to determine whether such 

 spawning periodicity actually exists in the deep 

 habitat (generally >730 m) of the adults. 



Specimens were collected in the upper 185 m or 

 less of the water column over bottom depths of 59 

 to 2,850 m, with the largest larva taken in a sur- 

 face (upper 10 m) tow (Table 1). The wide ranging 

 occurrences of the pelagic eggs and larvae between 

 9 and 111 km from the coast probably reflects drift 

 and dispersal by currents. 



The larvae appear to be rare, at least off Oregon, 

 based on over 3,000 midwater trawl and plankton 

 collections that have been taken in that region 



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