The family Peristediidae, comprising about 36 species of armored sea robins in five genera, inhabit the bottoms of the tropical and temperate waters of the world oceans in depths of about 50 to 800 m. The aim of this study is to infer relationships among the species in the family based on morphological characters and to revise the genus-level classification on the basis of the inferred pattern of phylogeny. Twenty-four peristediid and 16 outgroup taxa, i.e., 13 triglid and three hoplichthyid species, were used for the phylogenetic analysis. Monophyly of the Peristediidae is highly corroborated and two major clades are recognized in the family. The first clade includes Gargariscus, Heminodus, Satyrichthys, and Paraheminodus, and the second includes only Peristedion. It became clear that the genus Satyrichthys is a nonmonophyletic group. In conclusion, six monophyletic genera are recognized in the Peristediidae: Gargariscus, Heminodus, Paraheminodus, Peristedion, Satyrichthys, and Scalicus. Accordingly, I propose seven new combinations with Scalicus as follows: Scalicus engyceros, S. gilberti, S. hians, S. investigatoris, S. orientalis, S. quadratorostratus, and S. serrulatus.
Barrowgammarus macginitiei (Shoemaker, 1955) and Spasskogammarus spasskii (Bulycheva, 1952) are reported based on specimens from Hokkaido, northern Japan. These are the first records of these two genera n Japan. The single specimen referred to B. macginitiei differs from the original description in having a relatively short antenna 1, distally tapering coxa 1, long setae on the merus and carpus of pereopods 3 and 4, long, slender setae on the ventral margins of epimeral plates 2 and 3, marginal setae on the rami of uropods 1 and 2, a small protuberance on urosomite 3, and a single accessory lobe on the coxal gill of pereopod 6. The Japanese specimens of S. spasskii generally agree with the original description except for the presence of a few slender setae on the inner margin of the outer ramus of uropod 3.
Two new interstitial cytheroid ostracods are described from a small sandy beach in Shimoda, central Japan: Microloxoconcha ikeyai sp. nov. (Cytheromatidae) and Parvocythere japonica sp. nov. (Parvocytheridae). This is the first record of the genus Parvocythere Hartman, 1959 from Japan. By sampling every two months through a year along a transect extending from the shoreline landward across the study area, the optimal zone for each species was found. The peaks of individual density for M. ikeyai and P. japonica lie seaward and landward, respectively. Both species show a wide tolerance to changes in salinity, but they do not live where fine sand (mode of grain size less than 1/8 mm) is the dominant particle size. In assays of phototaxis, M. ikeyai, which has a naupliar eye, showed negative phototaxis.
The Japanese species of the chironomid midge genus Conchapelopia Fittkau, 1957 are reviewed based on a study of the type material and/or recently obtained specimens. The following eight species are recognized as valid: C. japonica (Tokunaga, 1937); C. amamiaurea Sasa, 1990; C. okisimilis Sasa, 1990; C. shikotuensis Sasa, 1990; C. unzenalba Sasa, 1991; C. togamaculosa Sasa and Okazawa, 1992; C. togapallida Sasa and Okazawa, 1992; and C. seiryusetea Sasa, Suzuki, and Sakai, 1998. The male and female imagines of Conchapelopia japonica and C. shikotuensis, and the male imagines of C. okisimilis, C. togamaculosa, and C. togapallida are redescribed, while the immature stages of these species and the female imagines of the latter three species are described for the first time. Reexamination of the holotypes of Conchapelopia amamiaurea, C. unzenalba, and C. seiryusetea has shown that the respective original descriptions contain errors in some diagnostic aspects, which are corrected in this study. Seven previously described taxa are found to be synonyms. Keys to male imagines and pupae of known Japanese species of Conchapelopia are included.