Distribution: Probably circumglobal in southern temperature waters. It is known from 

 near New Zealand, Valparaiso, Chile, and off South Africa. 

 Discussion 



The genus Metelectrona has been relegated to the synonymy of Electrona by some authors, 

 principally Becker (1967) and Paxton (1972). However I retain the genus principally because 

 of the statement of Moser and Ahlstrom (1974, p. 395) that the larva of Metelectrona resembled 

 larvae of the genus Hygophum in some features but had characters found in neither 

 Hygophum nor Electrona, and stated that, ". . . the uniqueness of the larva strongly suggests 

 the resurrection of Metelectrona as a valid genus." 



Becker, 1963a, based the species M. ventralis on two small specimens (26.2 and 25.3 mm) 

 that bore no luminous caudal glands. Wisner, 1963b, based M. alhstromi on a single adult that 

 bore a small, roughly square luminous gland on each surface of the caudal peduncle near the 

 first procurrent caudal ray. Counts and measurements of the two forms are very similar. 



Dr. P. Alexander Hulley, South Africa Museum, Cape Town, has recently informed me 

 that he had examined a large number of adults from the South Atlantic Ocean and found the 

 caudal glands to be similar to those described and figured for M. ahlstromi and was satisfied 

 that there was but one species. Publication of the name ventralis predates that of the name 

 ahlstromi by about 38 days (February 21 vs March 30, 1963). 



Fig. 22 — Metelectrona ahlstromi. sex unknown, 66.3 mm. 



Hygophum 



Tuning (In: Bolin, 1939) 



SAO markedly angulate. Two Pol; 2 Pre, widely separated, the upper usually near lateral 

 line. VO level: PO usually level, PO.-, slightly elevated in one species. Upper jaw broadly 

 expanded posteriorly, reaching little if at all past a vertical from posterior margin or orbit. 



Key to species of Hygophum 



la. AOa series distinctly curved 2 



lb. AOa series straight 3 



2a. PO.-, slightly but distinctly elevated. A line through Pol passes through or before next to 



last AOa. VLO well below lateral line. AOa series moderately curved H. bruuni 



2b. PO.-, not elevated. A line through Pol passes through or before first AOa. VLO very near 



lateral line. AOa slightly curved H. hygomi 



3a. A line through SAO,. 2 passes well below PVO,. Origin of pectoral fin below level of center 



of eye. Greatest depth of body about 25*^^ of SL. Upper jaw barely extends past hind margin 



of orbit H.proximum 



3b. A line through SAOi.^^ passes through or above PVOi. Origin of pectoral fin on or above 



level of center of eye. Greatest depth of body about 20'/f ofSL 4 



32 



