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ONTOGENY AND SYSTEMATICS OF FISHES -AHLSTROM SYMPOSIUM 



although their development is not known. (2) Those with in- 

 dividual, separate photophores that have a gradual, protracted 

 metamorphosis. This group includes Bonapartia, Margrelhia. 

 and Gonostoma. (3) Those with some individual photophores 

 but some or most of the photophores with common bases [ac- 

 tually a common lumen, during development at least] and hav- 

 ing a gradual, protracted metamorphosis. This group includes 

 Araiophos, Maurolicus, Danaphos, Valenciennellus, .Argyrip- 

 nus, Polyipnus, Argyropelecus, Sternoptyx, and presumably 

 Thorophos and Sonoda ahhough their development is unknown. 

 Groups (1) and (2) comprised the subfamily Gonostomatinae 

 and Group (3) comprised the Stemoptychinae in Ahlstrom's 

 concept. Group (3) is equivalent to Weitzman's Stemoptychi- 

 dae. The genus Gonostoma was considered "pivotal" by Ahl- 

 strom; that is, its relationships could be with either the gonos- 

 tomatines or the stemoptychines of his concept. In Ahlstrom's 

 conclusions, the photophore pattern of Group (1) is most like 

 that of the stomiid groups discussed by Fink in this volume. 



Weitzman's classification (1974) concentrated in most detail 

 on a hypothesis of phylogenetic relationships within the family 

 Stemoptychidae as he defined it. Weitzman (1974) pointed out 



that more detailed studies should be conducted on other sto- 

 miiform genera in the future, but he did discuss their possible 

 relationships. Based on the number of proximal pectoral-fin 

 radials, he established two infraorders for stomiiform fishes. 

 Members of the Infraorder Gonostomata were considered to 

 have four proximal pectoral-fin radials (except Cyclothone with 

 one). This infraorder was divided into two families based prin- 

 cipally on Bassot's photophore findings; Family Gonostomati- 

 dae with Beta type photophores comprised of Diplophos in- 

 cluding Manducus), Triplophos, Bonapartia, Margrethia. 

 Gonostoma, and Cyclothone and the Family Stemoptychidae 

 with Alpha type photophores comprised of Thorophos, Araio- 

 phos, Maurolicus, Danaphos, Valenciennellus, Argyripnus, Son- 

 oda, Polyipnus, Argyropelecus, and Sternoptyx. The problem 

 with Weitzman's Gonostomata is that it was based on a prim- 

 itive character for the stomiiforms, four pectoral-fin radials, and 

 this character cannot be used as a synapomorphy to define a 

 subgroup of stomiiforms. The non-stemoptychid and non-gon- 

 ostomatid genera, along with the stomiiform families possessing 

 barbels originating from the hyoid bone and lacking elongate 

 gill rakers in the adults (the Stomiidae of Fink, this volume). 



