Naoki Yagishita

Review of monophyly of the Kyphosidae (sensu Nelson, 1994), inferred from the mitochondrial ND2 gene

Abstract Girella, Kyphosus, Scorpis, and some other perciform fishes have been regarded as being related to each other. Nelson (1994) recognized them as the subfamilies under the Kyphosidae, but he did not show any synapomorphic characters uniting them. Johnson and Fritzsche (1989) suggested that the perciform group characterized by RLA pattern 10, namely, Girellidae, Kyphosidae (not of Nelson, 1994), Scorpididae, Microcanthidae, Kuhliidae, Arripidae, Oplegnathidae, Terapontidae, and families of the Stromateoidei, form a monophyletic group. We estimated the phylogenetic relationships of fishes of the group to review monophyly of the Kyphosidae (sensu Nelson, 1994) by partially sequencing the mitochondrially encoded NADH dehydrogenase subunit 2 gene. Labracoglossa-Scorpis, Oplegnathus, Kyphosus, Kuhlia, Microcanthus, and Girella constituted a single clade with relatively high reliability values for both the neighbor-joining (NJ) and maximum-likelihood (ML) trees, but the monophyly of Kyphosidae (sensu Nelson, 1994) was not supported. The group characterized by RLA pattern 10 formed a monophyletic group both in the NJ and ML trees here; however, additional basal perciform taxa need to be analyzed to resolve it more clearly.

Revision of the genus Girella (Girellidae) from East Asia

The taxonomy of three species ofGirella from East Asian waters,G. punctata Gray, 1835,G. leonina (Richardson, 1846) andG. mezina Jordan & Starks, 1907, is reviewed and intraspecific (individual and ontogenic) variations detailed.Girella mezina is characterized by a very wide mouth and thick upper lip, the soft-rayed portion of the anal fin high and round, dorsal profile of the head abruptly slanting in front of the eyes in adults, a transverse yellow band on the body in life, and 3–4 rows of teeth along the outer jaw margins, the central cusp of each tooth being wider than the lateral cusps in adults.Girella punctata is characterized by usually 2 rows of teeth along the outer jaw margins, usually 7 transverse series of scales between the lateral line and median spinous portion of the dorsal fin (TRac), and usually 52–55 pored lateral line scales (LLp). The species is variable in body and caudal fin shape, extent of squamation on the opercular region, and number and position of dark spots on the scales. It also exhibits ontogenetic variation in the number of tooth-rows.Girella leonina is characterized by a conspicuously black opercular flap, essentially a single row of teeth along the outer jaw margins, usually 10–11 TRac and usually 59–64 LLp. Intraspecific variations were evident in the mouth position, scale condition and body color after death, and in the number of pores of cephalic lateral line canals. The holotype ofG. punctata, previously known only from a figure, is described for the first time.Girella melanichthys is synonymized underG. punctata with a lectotype designated for the former.

Evolutionary trend in feeding habits of Girella (Perciformes: Girellidae)

Although some Girella species are herbivorous, having basically tricuspid teeth, some are omnivorous. To determine the evolutionary trends in feeding habits of Girella, the phylogenetic relationships of several species of Girella were estimated by partially sequencing the mitochondrially encoded NADH dehydrogenase subunit 2 gene, and the dentition and adductor mandibulae complex of each species were examined. The cladogram determined from the mitochondrial DNA analysis indicated that multiple tooth-rows containing incisor-like teeth existed in adults of the ancestral species of Girella, species with a single tooth-row of tricuspid teeth in the adult stage having diverged subsequently on several occasions. The tendinous connections between each section of the adductor mandibulae complex are believed to have been simple in the ancestral species, more complicated connections also having diverged later on several occasions. Multiple tooth-rows containing incisor-like teeth and the simple adductor mandibulae complex are deduced as adaptations to herbivory; on the other hand, a single tooth-row of tricuspid teeth and the complicated adductor mandibulae complex are deduced as adaptations to omnivory. Therefore, the ancestral species of Girella is suggested as having been adapted to herbivory, with species adapted to omnivory having diverged on several subsequent occasions.

Sexual dimorphism in Sebastes owstoni (Scorpaenidae) from the Sea of Japan

Morphological and genetic differences between red and yellow morphotypes of Sebastes owstoni were investigated, utilizing 277 males [84.0–194.3 mm in standard length (SL)] and 542 females (92.3–251.5 mm SL) from the Sea of Japan. All males smaller than 120 mm SL were characterized by red body color. The frequency of specimens with yellow body color thereafter increased gradually with SL, all specimens larger than 170 mm SL being yellow. The specimens with yellow body color were observed throughout the year. All females smaller than 170 mm SL were characterized by red body color, the frequency of specimens with yellow body color tending to slightly increase with SL. However, most females had red body color, except for 16 specimens (177.7–241.5 mm SL) that were yellow, growth-related color change from red to yellow being uncommon. Morphological analysis of 49 males (107.6–193.3 mm SL) and 68 females (108.7–241.5 mm SL) showed the head length, orbit diameter, lower jaw length, and predorsal length to be relatively greater, but the distance between the pelvic and anal fins less, in males. A discriminant analysis using Mahalanobis distances resulted in 100% correct assignment of specimens to sex, regardless of SL and body color. In addition, no genetic differences were apparent between red and yellow individuals in mitochondrial DNA sequence analyses from the threonine tRNA to the first half of the control region (498 bp). Accordingly, the differences in body color, maximum size, and the five morphometric characters listed above were considered to represent sexual dimorphism. That evidenced by body color was considered to appear after that shown by morphometric characters, some exceptions in the former occurring in females. This is the first report of permanent sexual dimorphism in body color in Sebastes.

Two additional paralectotypes of Crenidens melanichthys Richardson, 1846 (Girellidae)

Abstract Two of the seven original syntypes of Crenidensmelanichthys, RMNH 1224 and 1225, were not listed as paralectotypes in a previous work because they were believed to have been lost. However, the two specimens in question have recently been found in Rijksmuseum van Natuurlijke Historie, Leiden, and are accordingly listed here as additional paralectotypes of C. melanichthys. Their descriptions are also given.