ALLEN: GOBIESOCIFORMES 



635 



Dorsal Trunk (DT) 



Dorsal Head (DH) 



Lateral Trunk (LT) 



Postanal Ventral (PV) 



Dorsal Gut (DG) 

 Lateral Gut (LG) 



Fig. 338. Hypothetical clingfish larva showing regions which form the basis for coding patterns of melanophores. 



Ventral Gut (VG) 



flattened head, anterior pel vies, incomplete circumorbital series) 

 are the result of convergence. Gosline (1970) then cited five 

 morphological and osteological features which differ between 

 the Gobiesociformes (including the three families) and the Ba- 

 trachoidiformes. These features include differences in pelvic fin 

 structure and orientation, structure of the upper hypurals, as- 

 cending process of premaxilla, ossification of the median eth- 

 moid and presence (Batrachoidiformes) or absence (Gobiesoc- 

 iformes) of a swimbladder. On the other hand, he upheld that 

 gobiesociform (three families) fishes have almost all of the di- 

 agnostic characteristics of the superfamily Notothenioidca of 

 the perciform suborder Blennioidea (see Gosline, 1968). He 

 further pointed out structural similarities between members of 

 the Gobiesociformes and certain genera of notothenioid fishes 

 as evidence supporting this proposed relationship. Based on this 

 work on adults, gobiesociform fishes are currently considered 

 perciform derivatives in the superorder Acanthopterygii. How- 

 ever, the issue remains far from resolved and future investi- 

 gations into both the ordinal and superordinal relationships are 

 still very much in order. In fact, William Eschmeyer (California 

 Academy of Sciences) is currently investigating possible rela- 

 tionships between gobiesociform (particularly gobiesocids) and 

 scorpaeniform fishes (pers. comm.). 



The early life history stages of gobiesocids and callionymids 

 (see Houde, this volume) lend little support to Gosline's clas- 

 sification. Gobiesocid and callionymid larvae are usually pig- 

 mented heavily, but there are very few additional similarities 

 at the current level of examination. Gobiesocid and callionymid 

 early life history stages differ in: egg type (demersal versus pe- 

 lagic eggs, respectively), preanal length (>50% versus <50% of 

 standard length), general body shape (relatively large cylindrical 

 versus small, laterally compressed larvae), myomere/vertebral 

 counts (24 to 37 versus 19 to 23), and shape of the notochord 

 tip (no extension versus a long extension beyond the hypural 

 plate). These basic differences may, in part, represent divergence 

 due to dissimilar reproductive strategies. A more thorough, de- 

 tailed comparison of the early life history stages (larvae in par- 

 ticular) will be necessary before any solid conclusions can be 

 drawn. Unfortunately, the eggs and larvae of draconettids (pre- 

 sumably the most primitive members of the order) are unknown 

 and cannot help clarify the situation. 



The use of larval characteristics to assess higher level rela- 

 tionships between the Gobiesociformes and the Batrachoidi- 

 formes or Notothenioidea is limited since batrachoids have di- 

 rect development (no larval form) and the larvae of notothenioids 

 bear little, general resemblance to gobiesocid and callionymid 



Fig. 337, Representative larvae of six genera within the Gobiesocidae: (A) Gastroscyphus hectoris. 5.4 mm (after Ruck. 1976); (B) Gobiesox 

 rhessodnn. 6.2 mm (from Allen, 1979); (C) Rimuola miiscarum. 4.0 mm (from Allen, 1979); (D) Lepadichthys frenalus, 7.3 mm (from Shiogaki 

 and Dotsu, in prep.); (E) Aspasma minima, 6.8 mm (from Shiogaki and Dotsu, 1971a); and (F) Aspasmichlhys ciconiae. 6.9 mm (from Shiogaki 

 and Dotsu, 1972d). 



