Four specimens (168.6–204.4 mm standard length) of Careproctus lycopersicus Orr, 2012, previously recorded from the Bering Sea and eastern Aleutian Islands, were collected from the southern Sea of Okhotsk (the Nemuro Strait, eastern Hokkaido, Japan). These specimens represent the first records of the species from the western North Pacific. A detailed description is provided for the specimens, including the intraspecific variations. The new standard Japanese name “Tomato-kon’nyaku-uo” is proposed for the species.
The subgenus Setihenricia Chichvarkhin and Chichvarkhina, 2017 currently consists of 32 out of 94 species of sea stars in the genus Henricia Gray, 1840. However, only 10 have been molecularly ascertained as to the phylogenetic position. Based on seven mitochondrial gene markers (16S rRNA, COI, tRNA-Ala, tRNA-Leu, tRNA-Asn, tRNA-Gln, and tRNA-Pro), we performed molecular analyses to assess the monophyly of Setihenricia using 16 species of Henricia from Japanese waters, as well as other congeners for which sequences were available in public databases. The monophyletic Setihenricia was only weakly recovered because the support values were low, but we assume this taxon may be valid in consideration of a morphological key. Henricia kinkasana Hayashi, 1940 is herein identified as a new member of Setihenricia, based on molecular and morphological evidence. Sequences in the public databases previously identified as H. compacta (Sladen, 1889) and H. obesa (Sladen, 1889) were nested in the Setihenricia clade; these two species are also likely members of Setihenricia. Our morphological assessment yielded three findings: (1) the number of the rows of spines on each inferomarginal plate, being three or more, appears to be a useful diagnostic character for Setihenricia, as has been suggested in previous studies, (2) the degree of spine tapering turned out to be less relevant in diagnosing the subgenus than previously supposed, (3) two newly introduced characters—(i) the width of adambulacral plates and (ii) the ratio of two measurements in ambulacral plates to the length of interradius—may be effective to distinguish members of this apparent Henricia subclade from other members of the genus.
We describe a new species of polyclad flatworm, Prosthiostomum torquatum sp. nov., from the rocky intertidal zone in Shirahama, on the Pacific coast of middle Honshu, Japan. Prosthiostomum torquatum is characterised by a unique dorsal colouration, which is comprised of i) numerous orange maculae and blue dots dispersed all over the dorsal surface, ii) a transverse dark-brown line in the anterior part of the body running slightly anterior to another transverse white line, both of which are slightly bent backwards at mid-point, and iii) an incomplete, mesh-like, median band made by dark-brown pigments, fading away posteriorly. By this dorsal colour pattern, the new species can be distinguished from similar congeners such as P. trilineatum Yeri and Kaburaki, 1920 and P. komaii Kato, 1944. We performed a molecular phylogenetic analysis based on 462-bp partial mitochondrial cytochrome c oxidase subunit I (COI) sequences of four species of Prosthiostomidae currently available in public databases in addition to that of P. torquatum. In the resulting tree, P. torquatum was sister to Lurymare clavocapitata Marquina, Aguado, and Noreña, 2015 originally described from Lizard Island, Australia. While these two share a similar dorsal colouration, P. torquatum can be distinguished from L. clavocapitata by i) the absence of a common muscle bulb/sheath enclosing the whole male copulatory apparatus, ii) the median mesh-like band comprised of dark-brown pigments, and iii) COI uncorrected p-distance being 0.094. As a result, our phylogenetic tree indicates the possibility that Prosthiostomum and Lurymare as currently diagnosed may not be monophyletic, and that the common muscle bulb enclosing the whole male copulatory apparatus may not be appropriate as a diagnostic character for Lurymare.
Neoheterocotyle quadrispinata n. sp. (Monogenea: Monocotylidae) is described from the gills of Rhinobatos hynnicephalus Richardson, 1846 (Rhinopristiformes: Rhinobatidae) in the central Seto Inland Sea, Hiroshima Prefecture and the southern Sea of Japan, Fukuoka Prefecture, Japan. This is the first report of a Neoheterocotyle species from Japan. The new species is morphologically most similar to N. forficata (Timofeeva, 1981) and N. rhinobatidis (Young, 1967) in having two pairs of dorsal haptoral accessory sclerites but differs from them in that the penis is curved proximally and the accessory piece has a blade-shaped process.
The primarily Indo-West Pacific echiuran Listriolobus brevirostris Chen and Yeh, 1958 was collected, sometimes abundantly, from benthos samples from northeastern Osaka Bay (from 6.4–17.5 m depth) between 1999 and 2001, or recorded in the field between 1995 and 2002. Since 2003, it has remained uncollected. These records were shown to represent the first occurrence of L. brevirostris in Japanese waters, being the first reliable evidence so far determined of the introduction of an exotic echiuran species, probably in ballast water, to any locality worldwide. Aquarium observations suggested a completely infaunal adult life mode, including feeding activity. Monthly changes in size distribution of specimens collected in 1999 indicated successful summer survival under oxygen-depleted bottom conditions in Osaka Bay. Factors behind the ephemeral occurrence of L. brevirostris in Osaka Bay were briefly considered in relation to annual fluctuations of dissolved oxygen content in bottom water, although the driving forces behind such occurrence remain to be established.
Members of the genus Glaphyrostomum Braun, 1901 (Trematoda: Brachylaimidae) are parasites of birds. However, an exception occurs in Glaphyrostomum soricis Asakawa, Kamiya and Ohbayashi, 1988, which was described from the long-clawed shrew, Sorex unguiculatus Dobson, 1890, in Hokkaido, Japan. A recent DNA barcode-based trematode survey of land snails clearly showed that Ainohelix editha (A. Adams, 1868), a bradybaenid snail indigenous to Hokkaido, serves as the first and second intermediate hosts for a species of the genus Pseudoleucochloridium Pojmańska, 1959 (Panopistidae). Its adult stage was furthermore confirmed from S. unguiculatus. A comparison of adult morphology between Pseudoleucochloridium sp. and G. soricis revealed that both should be considered the same species. However, Pseudoleucochloridium soricis comb. nov. cannot be applied because P. soricis (Sołtys, 1952) already exists as the type species of the genus. We, therefore, propose Pseudoleucochloridium ainohelicis nom. nov. as a replacement name for G. soricis.
Although Scorpaena dabryi Sauvage, 1878, originally described on the basis of two specimens from China, has recently been regarded as a senior synonym of Neomerinthe procurva Chen, 1981, examination of the specimens (herein designated as lectotype of S. dabryi) showed them to be consistent with the holotype and non-type specimens of S. miostoma Günther, 1877. Accordingly, S. dabryi is regarded as a junior synonym of S. miostoma. Morphological ontogenetic changes of some body proportions in S. miostoma are also described.
The genus-group name Curtipleon Bǎcescu, 1976 is not available due to Bǎcescu’s failure to fix its type species in the original publication. This genus-group name should be attributed to Sieg (1983)—the work accidentally validated the genus-group name under Article 13 of the International Code of Zoological Nomenclature.