FISHERY BULLETIN: VOL. 85, NO. 2 



This condition has been illustrated in one other lar- 

 val sculpin (Matarese and Marliave 1982, Fig. 2E), 

 but may be variable. By the juvenile stage the neural 

 element(s) appear as one broad, ossified spine (Fig. 

 4D). 



Hemal spines form in unison with the neural 

 spines. The hemal spine on the first pre-ural cen- 

 trum develop an elongate, descending process to 

 which several procurrent rays articulate. A similar 

 elongate structure was identified as the parhypural 

 in Icelus spiniger (Nelson 1984). The present study 

 agrees with Materese and Marliave (1982) and Yabe 

 (1985) in identifying the process as part of the hemal 

 spine because it is always associated with the spine 

 during development. 



Twelve principal caudal rays develop and articu- 

 late with the hypural plates during flexion (Fig. 4B). 

 The number of these rays varies in other sculpins 

 from 11 to 13 (Materese and Marliave 1982; Nelson 

 1984). 



Procurrent rays form after flexion (Fig. 4C) and 

 increase in number to a maximum of 10 for the up- 

 per procurrent rays and 8 for the lower procurrent 

 rays. The last lower procurrent ray appears to ar- 

 ticulate with a radial cartilage between the posterior 

 tip of the descending hemal spine process and the 

 an tero ventral edge of the inferior hypural plate. 



Three epurals form dorsal to the ural-centrum in 

 the postflexion larvae and are also present in juve- 

 niles and adults. A uroneural appears dorsal to the 

 reduced urostyle in the juveniles (Fig. 4D). 



Occurrence 



Icelinus quadriseriatus larvae were collected in 

 every month of the year with peak occurrence from 

 May to June in 1979, which is in agreement with 

 peak occurrence of prespawning females (Goldberg 

 1980) for 1977, allowing for a time lag between 

 prespawning condition and hatching of the larvae; 

 the larvae are assumed to be planktonic for about 

 2 months. Peak spawning periods may vary yearly. 

 Goldberg (1980) reported a winter peak of oocyte 

 development that was earlier in 1978 (January- 

 April) than in 1977 (March-June). 



In the Southern California Bight, I. quadriseri- 

 atus larvae seemed to be concentrated in deeper 

 waters away from the intertidal and shallow sub- 

 tidal areas. Of the 33 bightwide discrete depth sam- 

 ples (nueston, middepth, and epibenthic) collected 

 in 1979 in which /. quadriseriatus occurred, only 2 

 samples were taken at the 8 or 15 m depth stations. 

 Ten samples were taken at the 22 m stations and 

 21 samples were taken at the 36 m station. 



Icelinus quadriseriatus larvae were generally 

 found near the bottom of the water column. Of the 

 33 discrete depth tows taken in which /. quadriseri- 

 atus larvae were found, 31 were epibenthic tows and 

 two were middepth tows. 



The bottom temperature at stations where /. 

 quadriseriatus larvae occurred ranged from 1 1 ° to 

 14 °C. Since the larvae were usually found at the bot- 

 tom, this suggests that these are the temperatures 

 under which they normally develop in the field. 

 Reared larvae were observed to survive aquarium 

 temperatures of at least 18°C. 



DISCUSSION 



Fertilization 



Many cottids, including Chitonotus and Oligocot- 

 tus snyderi, practice internal fertilization facilitated 

 by an intromittent male sex organ (Morris 1956; 

 Hubbs 1966; Stein 1973; Misitano 1980). Bolin (1941) 

 reported that Orthonopias triads has internal fer- 

 tilization even though the males do not have an ex- 

 ternal penis. Apparently the female has a "protrusile 

 oviduct" which is probably smeared with sperm and 

 then retracted. Fertile eggs have been removed 

 from females of Scorpaenichthys marmoratus and 

 Icelirms filam,entosus (Hubbs 1966). Icelinus quadri- 

 seriatus males possess no external penis and since 

 no females were found with fertile eggs, it is still 

 questionable as to what mode of fertilization these 

 sculpins possess. It is possible that /. quadriseriatus 

 has external fertilization (a rarity among sculpins), 

 but until the mating process is observed or an in- 

 ternally fertilized female is found, this question will 

 remain unanswered. 



Comparison with Other Sculpin Eggs 



The eggs of /. quadriseriatus are adhesive, de- 

 mersal, and share many characteristics with other 

 cottid eggs. The presence of a flocculant mass in- 

 side the yolk has been observed in several other 

 genera such as Chitonotus, Orthonopias, Clinocot- 

 tus, and Leptocottus (BoHn 1941; Morris 1951; Jones 

 1962; Misitano 1980). Multiple oil globules that 

 coalesce to one globule are common in other scul- 

 pins; however, I. quadriseriatus does have the high- 

 est initial number of oil globules (15) recorded in the 

 literature. The diameters for /. quadriseriatus eggs 

 are closest to the diameters of A7'tedius lateralis and 

 Clinocottus analis eggs (Budd 1940). 



The pale-green color of the yolk and the pigmen- 

 tation of the late-stage embryo are most similar to 



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