ABSTRACT
A small family of meso-, bathypelagic fishes known from the Atlantic, Indian, and Pacific Oceans comprised of three genera and four species of which all but one species is known from our area. The species are listed in Table Beryciformes 1 with their meristic characters. Adults are deep bodied, compressed, with very large eyes, well developed auditory bullae, and delicate head bones that are easily damaged. Minute spines are located near the bases of the dorsal and anal fins. Larval series are known for each species (Post & Quero 1981). The young stages are characterized by being relatively elongate at <4-5 mm then rapidly becoming deeper bodied; short, stout, rugose spine on the frontal bone over each eye; a longer, rugose, posteriorly directed, parietal spine on each side of the head; and a long, ventrally directed preopercular spine (Keene & Tighe 1984). In addition, they lack spines on the maxilla, retroarticular, branchiostegals, supraoccipital, supracleithrum, sub-, inter-, opercle, the latter with a non-serrate ridge (Baldwin & Johnson 1995). Post & Quero (1981) provided a key to young stages that relies on the alignment of the preopercular spine and color pattern. In small larvae the preopercular spine is directed posteroventrally in D. argenteus, but directly ventrad or anteroventrally in the other two species. In our paper (Lyczkowski-Shultz et al 2000) we showed a photo of a Diretmus argenteus that differed from described species by having a banding pattern not previously described. Post & Quero (1981) used color patterns to separate the other two species indicating that Diretmoides pauciradiatus has a brown spot above the posterior part of the anal fin and lacks a brownish, lateral trunk, horse shoe shaped area whereas Diretmichthys parini lacks the anal fin spot but has the brownish, horse shoe shaped area on its flank (best seen in Figure Diretmidae 3 G). We have reproduced the photographs from our paper together with other examples of all the species from other sources in Figures Diretmidae 1-3. The quality of the illustrations taken from Post & Quero (1981) is low, but the diagnostic features are revealed. Watson (1996ad) described D. argenteus from the California Current region and we include his figure of a 6.2 mm larva below (Figure Diretmidae 1, J).
