RICHARDSON: CURRENT KNOWLEDGE OF SCULPIN LARVAE 



ately pointed snout, relatively deep body, and long 

 gut. Larvae are quite large, ca. 12-14 mm NL, at 

 hatching. The larvae of H. americanus from the 

 Atlantic and H. villosus from Japan (Table 1) are 

 very similar. The heavy body pigment is a char- 

 acter shared with a number of apparently un- 

 related cottid genera. The genus was considered to 

 constitute a separate family, Hemitripteridae, by 

 Jordan (1923) and Taranets (1941). 



DISCUSSION 



The present state of cottid systematics is con- 

 fused and the group and its allies are in need of 

 intensive study (Nelson 1976; Howe and Richard- 

 son footnote 3). Family limits are not well defined 

 (compare, e.g., Jordan 1923; Berg 1940; Taranets 

 1941; Greenwood et al. 1966; Bailey et al. 1970; 

 Nelson 1976). Some genera still need revision and 

 potential new species remain to be described (e.g.. 

 Nelson 1977; Richardson and Washington 1980; 

 Howe and Richardson footnote 3). Studies of 

 intergeneric relationships have been few (e.g., 

 Regan 1913; Taranets 1941; Bolin 1947; Watanabe 

 1960) and these had many disagreements (Table 

 3). Jordan and Evermann's (1898:1879-1800) com- 

 ment of North American Cottidae still has merit, 

 "The family is an extremely varied one which 

 cannot be readily throvvoi into subordinate groups. 

 Almost every species has an individuality of 

 its own " 



Because of the confused state of cottid system- 

 atics it seems reasonable to consider whether this 

 preliminary summary of 25 genera of cottid larvae 

 may provide insight into intergeneric relation- 

 ships within the group. Whether these pheneti- 

 cally derived larval groupings are indicative of 

 relationships among cottid genera depends on 

 whether the groups actually possess a set of 

 shared, derived characters. Determination of de- 

 rived states of larval characters is difficult when 

 dealing with such a diverse group as the cottids 

 and their allies because the larvae of many species 

 are still unknown and complete developmental 

 series have not been described for many other 

 species. Such determinations are further hindered 

 by the confused state of adult cottid systematics. 

 Although an in depth analysis of derived charac- 

 ter states is beyond the scope of this study, 

 consideration of several factors allows discussion 

 of the potential significance of, and possible rela- 

 tionships within, at least some of the larval cottid 

 groups described here. Larval characters such as 



spine patterns, relative body form, and pigmenta- 

 tion have been used to demonstrate or clarify 

 systematic relationships in other groups of fishes, 

 e.g., scorpelarchids (Johnson 1974), gonostomatids 

 (Ahlstrom 1974), myctophids (Moser and Ahl- 

 strom 1974), myctophiforms (Okiyama 1974), ma- 

 rine teleosts in general (Ahlstrom and Moser 

 1976), bothids (Futch 1977), scombroids (Okiyama 

 and Ueyanagi 1978), serranids (Kendall 1979). In 

 these studies, similarity of larval form has been in 

 remarkable agreement with relationships implied 

 from adult characters. Although larval characters 

 have not been used previously as indicators 

 of relationship (i.e., based on synapomorphies) 

 among cottids, it seems highly probable that at 

 least some of these characters would be as useful 

 in cottids as in other groups of fishes. In addition, 

 if the cottids were derived from an ancestral stock 

 related to the Scorpaenidae, the most generalized 

 group in the Order Scorpaeniformes (Gill 1889; 

 Taranets 1941; Bolin 1947) and if Bolin's (1947) 

 ancestral cottid form is valid and Scorpaenichthys 

 closely resembles the primitive condition, then 

 primitive or derived states of at least some larval 

 characters of cottids can be postulated. Primitive 

 states of larval characters may include four strong 

 preopercular spines, relatively deep but compact 

 body, compact gut, lack of gut diverticula, posses- 

 sion of a preanal fin fold, rounded snout, relatively 

 short pectoral fin. Derived character states may 

 include reduced size and/or numbers of preoper- 

 cular spines or modification of the basic pattern of 

 four, slender or globose body, trailing gut, pres- 

 ence of gut diverticula, no preanal fin fold, semi- 

 pointed or pointed snout, elongated pectoral fin. 

 Pigment patterns are more difficult to evaluate as 

 presumably they may possibly reflect responses to 

 habitat or may be more easily modified genetical- 

 ly than other morphological characters. This idea 

 has been generally discredited in other groups 

 where larval characters have been used to imply 

 relationships (e.g., Ahlstrom 1974; Moser and 

 Ahlstrom 1974; Kendall 1979) as pigment patterns 

 have substantiated findings based on other char- 

 acters. Recent experiments on larvae of the zebra- 

 fish, Brachydanio rerio, (Milos and Dingle 1978) 

 have demonstrated constancy in numerical regu- 

 lation of melanophores which indicates larval 

 pigment patterns may not be as plastic as once 

 thought. Among the cottids, Scorpaenichthys is 

 heavily pigmented but Enophrys, also considered 

 to be a relatively primitive form (Sandercock and 

 Wilimovsky 1968), is not. Heavy pigmentation 



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