The T. trichodon eggs were amber colored and 

 large in size (3.52 mm in diameter ±0.10 SE, n = 

 17 eggs), and slightly flattened at points of at- 

 tachment. About 25% of the collected eggs were 

 dead at the time they were taken. When collected 

 the embryos had developed both melanic choroid 

 pigment and guanine iris pigment on the eyes. 



Considering the state of development of these 

 embryos, it was expected that these eggs would 

 mature and hatch within a month after collection, 

 since benthic egg masses of many northeast 

 Pacific fishes mature to hatching within 1 to 3 mo 

 after fertilization (pers. obs. on 28 species). The T. 

 trichodon eggs, however, continued to develop for 

 over 8 mo after they were collected, then all 

 hatched within a 24-h period. 



As a basis for comparison, wolf-eel, Anar- 

 rhichthys ocellatus, eggs are large (ca. 5 mm in 

 diameter) and have a relatively long incubation of 

 3 mo at 10°-12° C (pers. obs. on captive spawn). At 1 

 mo after fertilization (one-third of incubation 

 period), A. ocellatus embryos reach a devel- 

 opmental state comparable with that of the T. 

 trichodon at the time of the collection, with pig- 

 mented eyes on an embryo still many times small- 

 er than the yolk sac. Assuming comparability in 

 relative rates of development, a full incubation 

 period of 12 mo could therefore be calculated for 

 the T. trichodon. An incubation period of 1 yr 

 would indicate February as the time of spawning, 

 which coincides with the finding of a ripe female in 

 February in the same area of Vancouver Island 

 (Clemens and Wilby 1961). 



About 90% of the hatch occurred within 4 h, in 

 late afternoon, the remainder the next morning. 

 The T. trichodon eggs had not been handled for 2 

 wk prior to hatching and no other fish eggs had 

 hatched in the incubation tank for a week prior to 

 this hatch, so it appears unlikely that this abrupt 

 hatch was unnaturally stimulated. Only a few egg 

 mortalities occurred during the incubation period 

 in the laboratory; this low egg mortality, together 

 with the occurrence of an abrupt and fully viable 

 hatch, indicates that the observed incubation 

 period was normal for this species, as an abnormal 

 incubation should adversely affect viability. Al- 

 though incubation periods of about 1 yr have been 

 reported for an unrelated fish species, Agonus 

 cataphractus (see Breder and Rosen 1966 for re- 

 view), such prolonged incubation is evidently rare. 



The larvae were reared in the laboratory from 

 hatching through metamorphosis with no mor- 

 talities (maximum age 29 mo, 137 mm SL). Larvae 



hatched on 15 and 16 February 1977 at 14.5 mm SL 

 (16 mm TL) and grew to 40-43 mm SL (45-50 mm 

 TL) in 70 d, by which time the fish resembled small 

 adults. Allometric growth in the deeping and 

 lateral compression of the ventral body continued 

 to about 50 mm SL, along with upturning of the 

 jaw and development of fringed lips, as shall be 

 discussed in the following section. 



Immediately upon hatching the larvae swam to 

 the water surface and began schooling at the sur- 

 face in a two-dimensional array (one-fish deep). 

 This neustonic schooling behavior shifted to a pat- 

 tern of subsurface schooling (three-dimensional 

 schools, usually within 10 cm of the surface) at 

 about 48 h after hatching. At this time, feeding 

 was first noted. By 72 h after hatching, about half 

 the larvae had food in the guts within 4 h of the 

 daily food introduction; about 80% had full guts 

 after introduction of food on day 4 (96 h). Schooling 

 behavior was characteristic of the entire period of 

 larval development; these schooling tendencies 

 decreased progressively during metamorphosis 

 (from about 30 to 50 mm SL) and the juveniles did 

 not show true schooling behavior in the confines of 

 aquaria. 



The larval T. trichodon were rapid swimmers. 

 Alexander ( 1967 ) mentioned 10 body lengths/s as a 

 maximum burst speed for teleosts of any size and 

 3-5 body lengths/s as a maximum sustained speed 

 (maintained for at least several minutes). Al- 

 though no effort was made to determine precisely 

 the cruising speed of larval T. trichodon, observa- 

 tions of the distance traversed in 5 s intervals re- 

 vealed a cruising speed of about 10 body lengths/s 

 and always over 5 body lengths/s. This rapid 

 swimming occurred abruptly upon hatching, be- 

 fore the onset of feeding. Synchronized hatching, 

 the abrupt onset of schooling, and rapid swimming 

 may have evolved as mechanisms for larvae to 

 escape the physical dangers of the wave-swept in- 

 cubation site. 



Trichodon trichodon first burrowed into sand as 

 metamorphosed juveniles of 50-60 mm SL. They 

 burrowed by simultaneously undulating the body 

 laterally while fanning the pectoral fins upward 

 and forward, so that the body sank downward and 

 backward into the sand. The eyes and nostrils 

 usually remained exposed above the sand, al- 

 though the entire body could be buried. Burrowing 

 did not occur until fleshy fringes had developed on 

 the jaws. The fringed lips may permit water to be 

 inhaled without allowing sand to enter the buccal 

 cavity. The allometric growth prior to inital bur- 



960 



