AHLSTROM ET AL.: GONOSTOMATIDAE, STERNOPTYCHIDAE 



193 



Fig. 100. Lateral views from top to bottom: Bonapar/ia pedaliota 1 1 .5 mm SL. R/V OREGON II Cr. 1 26, Sta. 36688. 26°00.5'N, 088''00.4'W, 

 April 20, 1982, drawn by J. C. Javech; Margrethia obtusirostra 6.7 mm SL, R/V OREGON II Cr. 126, Sla. 36773. 26°00.rN, 094°00.2'W, May 

 23, 1982, drawn by J. C. Javech. 



were placed in the Infraorder Photichthya. Nearly all have three, 

 or rarely fewer, proximal pectoral-fin radials, a specialized char- 

 acter which can be used as a synapomorphy uniting this group. 

 As noted above, there are a few exceptions which bear four 

 proximal radials but these appear to be either reversals or are 

 neomoiphic. Within the Infraorder Photichthya the stomiiform 

 genera with elongate gill rakers in adults were placed in the 

 Family Photichthyidae comprised of the genera Polymetme. 

 Yarella. Pollichthys. Pholichlhys. Vinciguerria. Woodsia, and 

 Ichthyococcm. This placement was done on the basis of the 

 presence of Type Gamma photophores in at least most of the 

 genera, a specialization for the group (as well as for at least some 

 of the stomiid genera) and therefore a synapomoiTahy. The pres- 

 ence of elongate gill rakers in this group is not a synapomorphy 

 because it is primitive for the group. 



Essentially, Ahlstrom and Weitzman disagreed on the rela- 

 tionships of three genera. Alhstrom's Group ( 1 ) was mostly 

 equivalent to Weitzman's Photichthyidae but included three 

 genera, Cyclothone, Dtplophos (including Manducus), and Trip- 

 lophos. placed in the Gonostomatidae by Weitzman. Otherwise, 

 Weitzman's Gonostomatidae was equivalent to Ahlstrom's 

 Group (2). Based on evidence available to Ahlstrom and Weitz- 

 man, on some supplementary evidence provided by Fink and 

 Weitzman (1982), and on some of our own data, we here present 

 a somewhat different arrangement based on a more rigorous 

 phylogenetic analysis than done by Weitzman (1974). It turns 

 out that Weitzman's analysis of the Stemoptychidae and its 

 genera is consistently phylogenetic but that of outgroup sto- 

 miiforms is not. Ahlstrom (1974) did not attempt to analyze 

 his groups phylogenetically. The evidence available now seems 



to resolve the conflict between Ahlstrom (1974) and Weitzman 

 (1974). However, we would note that the analysis below is to 

 be regarded as a guide to future studies rather than any sort of 

 well-corroborated phylogeny. Parts, at least, of the arrangement 

 need much additional study. Furthermore, the relationships of 

 the genera in contention by Ahlstrom and Weitzman are still 

 not fully clear. Some of these genera, Manducus, Diplophos. and 

 perhaps Triplophos, are relatively primitive within stomiiforms 

 with few characters specialized beyond the stomiiform level. 

 This makes placing them in stomiiform subgroups difficult. Cy- 

 clothone is more derived but retains certain primitive stomi- 

 iform features and its relationship, although in our view is un- 

 doubtedly with the gonostomatids, at this time is somewhat 

 uncertain because our data are not fully analyzed. 



The conflict between Ahlstrom (1974) and Weitzman (1974) 

 arose in part because they both utilized one or the other of 

 certain characters. Type Beta photophores and "white" pho- 

 tophore development, as though they were shared specialized 

 characters, synapomorphies indicating relationships. Instead, 

 we believe these features are plesiomorphous for stomiiform 

 subgroups and cannot be used to support a hypothesis of rela- 

 tionships among stomiiform genera. Our current analysis is as 

 follows. 



Fink and Weitzman (1982:69-75) list and discuss eight syn- 

 apomorphies for stomiiform fishes. One of these, stomiiform- 

 type photophores, was described in some detail based in part 

 on Bassott (1966, 1971). Bassot (1966:574-576), Weitzman 

 ( 1974:338), and Fink and Weitzman ( 1 982:70) recognized Type 

 Beta photophores as primitive for stomiiforms. Bassot (1966, 

 1971) recognized two other types of photophores. Type Alpha 



