FISHERY BULLETIN: VOL. 79, NO. 1 



Table l. — Collection data for eggs and larvae of Embassichthys bathybius. 



Depth at anus = vertical distance from dorsal 

 body margin, excluding finfold or fin, to anus. 



Depth behind anus - vertical distance from 

 dorsal body margin to ventral body margin, 

 excluding finfold or fin, at point immediately be- 

 hind anus where body depth decreases greatly 

 compared with depth at anus. 



Body lengths refer to standard length. Illustra- 

 tions were made with the aid of a camera lucida. 



IDENTIFICATION 



The largest larva in the series, obviously a 

 pleuronectid based on general body form and 

 asymmetrical position of the left eye, had 60 myo- 

 meres (equivalent to vertebrae), 112 dorsal fin 

 rays, and 97 anal fin rays. Embassichthys 

 bathybius is the only pleuronectid occurring in the 

 northeast Pacific which has these counts (Norman 

 1934; Miller and Lea 1972; Hart 1973). The larval 

 series was linked together by the high number of 

 myomeres and by pigment pattern, most notably 

 three postanal pigment bands. Advanced embryos 

 in the eggs had the same pigment pattern as the 

 smallest larvae and the same high number of 

 myomeres, providing positive identification. 



DESCRIPTION 



Eggs (Figure 1) 



Two eggs identified as E. bathybius are spheri- 

 cal and transparent, 3.0 mm in diameter, with a 

 homogeneous yolk, a relatively narrow peri vitel- 

 line space, and no oil globule. The egg membrane 

 is smooth and has a slight pinkish tinge in pre- 

 served material. Both eggs have well-developed 

 embryos with three distinctive postanal pigment 

 bands, including one at the tail tip. In the more 

 advanced embryo (illustrated), the eyes are pig- 

 mented and the postanal bands are more intense. 

 Pigment also occurs near the hindgut and extends 

 out onto the yolk. 



Figure l. — Egg of Embassichthys bathybius, 3.0 mm 



in diameter. 



Larvae (Figure 2; Table 2) 



Six larvae identified as E. bathybius range from 

 9.8 to 16.2 mm SL. The two smallest specimens 

 appear to be recently hatched, based on state of 

 development compared with the most advanced 

 embryo. A hatching size of about 9 mm (excluding 

 shrinkage due to Formalin preservation) may be 

 reasonable, based on the diameter-circumference 

 relationship for a 3.0 mm diameter egg and the 

 extent to which the advanced embryo encircles the 

 yolk mass (Figure 1). The largest specimen, 16.2 

 mm, is beginning to undergo transformation as 

 evidenced by the slight asymmetrical position of 

 the left eye. The size at which the transformation 

 process is complete is unknown. 



Pigmentation on the smallest larvae is similar 

 to that on the embryos, with melanophores pres- 

 ent over the hindgut and in three bands postanally. 

 Pigment in the anterior two of these three bands is 

 generally more concentrated along the dorsal and 



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