74 



ONTOGENY AND SYSTEMATICS OF FISHES-AHLSTROM SYMPOSIUM 



Table 14. 



Pigment and Morphological Characters of the Synaphobrachoidea. 



to Fig. 34. 



+ = All or most species; ( + ) = some species only. Refer 



Gut pigment 

 H. Absent 



1. An irregular series of dendritic 

 melanophores along its length 



Morphological 

 J. Posterior flexures of myomeres 

 rounded 



An opaque midlateral area of 

 myomeres along length of body 

 Posterior flexures of myomeres 

 angular 



Rostrum absent 

 Rostrum present 

 Gut straight 



Gut swollen or lightly arched 

 at points along its length 

 Posterior end of gut markedly 

 flexed downwards 



K. 



M. 

 N. 

 O. 

 P. 



(+) 



+ 



+ 

 + 



+ 

 + 



+ 

 + 



+ 

 + 



(+) 



+ 

 + 



+ 

 + 



(+) 

 (+) 

 (+) 

 (+) 

 (+) 

 (+) 



+ 

 + 



+ 



(+) 



(+) 

 (+) 

 (+) 

 (+) 

 (+) 

 (+) 



+ 

 + 



+ 

 + 



However, this character is not generally applicable in larval 

 identification because of forward movement of the anus during 

 metamorphosis in some species. 



The gut is most often a narrow straight tube, flexed down- 

 wards under the pectoral fin and following the ventral margin 

 to the posteriorly placed anus. The stomach is usually visible 

 as a finger-like sac at about segment 10. The most frequent 

 modifications of the gut tube are loops or swellings at intervals 

 along its length, each usually accompanied by groups of mela- 

 nophores (Ophichthidae, Tables 15-16 and Figs. 35, 36; Ac- 

 romycter. Table 18 and Fig. 38; some Nettastomatidae, Table 

 19 and Fig. 39). The number and state of development (low, 

 moderate or conspicuous) of the swellings may be diagnostic at 

 family, genus or species level but is not always so (Leiby, 1981). 



The liver, with associated gall bladder, fills much of the space 

 anteriorly between the gut and the ventral margin of the lateral 

 muscles. It has two or three lobes in the Ophichthidae (Table 

 15 and Fig. 35), the gall bladder on the second or third lobe, 

 and the lobes may be distinct or connected by a thin band of 

 liver tissue. 



Larval pigment is present in larvae of all families except the 

 Anguillidae and may be highly elaborated to form complex and 

 distinctive patterns. The pigmentation, if present, is usually much 

 simpler in the engyodontic stage than later stages. Melanophores 

 may begin to appear in the embryo (in some Ophichthidae as 

 several pigment patches on the gut similar to those in the larvae; 



in some Muraenidae on the spinal cord) but typically do not do 

 so until the early engyodontic stage. Pigmentation sometimes 

 reaches its full expression by the beginning of the euryodontic 

 stage but typically the complex patterns characteristic of the 

 Ophichthidae and other families are not complete until full 

 larval growth. Subsequently pigment may be lost during meta- 

 morphosis (the congrid Ahosoma), but may serve as a highly 

 important character in matching larvae with adults. 



Individually, melanophores may be dendritic (Dysommati- 

 dae. Table 14 Ci-C, and Fig. 34). ocellate (Congridae, Table 

 18B and Fig. 38B), compact (Muraenidae, Table 21 D and Fig. 

 4 1 ) or rather diffuse (Moringuidae, Table 23 C, and Fig. 43). They 

 may be isolated, grouped in clusters to form conspicuous pig- 

 ment patches (the congrid Bathymynis. Table 1 7G and Fig. 37), 

 or they may form well defined lines, series or patterns. In most 

 families they occur on the lateral body surface, including the 

 caudal fin, on the myosepta (Ariosoma, Table 17E and Fig. 37; 

 Bathymyrus. Table 1 7E and Fig. 37; many Ophichthidae, Table 

 16 and Fig. 36), or on the ventral body wall (Dysommatidae, 

 Table 141 and Fig. 34; Congridae, Table 18Land Fig. 38). They 

 may occur deeper in the tissues, either on the gut, liver, kidney, 

 suspended in the mucinous space between the lateral muscles, 

 associated with the spinal cord or vertebral column or, fre- 

 quently, on the bases of the caudal, anal and dorsal fin-rays. 



Although Blache (1977) and Fahay and Obenchain (1978) 

 have attempted to summarise pigment patterns in some groups 



