A single specimen of Photonectes (Stomiidae: Melanostomiinae), collected from Suruga Bay, Pacific coast of central Japan in 1966, was identified as Photonectes cyanogrammicus Prokofiev and Klepadlo, 2019, previously known only from the holotype, collected from the Solomon Islands, the present specimen therefore being the second record of the species and first Northern Hemisphere record. The species is separable from congeners as follows: barbel short, unbranched, unpigmented distally, and lacking a terminal bulb and appendage; postorbital photophore (PTO) not reaching below center of eye; last two VAV photophores situated higher than other VAV photophores; streak-like blue or white luminous tissue extending between each IV photophore; and no luminous patches inside mouth. The longitudinal streak-like luminous tissue was observable only above the first and second PV photophores in the present specimen, although the original description indicated the tissue was clearly visible above the first to eighteenth PV photophores, the difference likely being attributable to bleaching of the present specimen during its long-time preservation. An additional Photonectes specimen, recently collected off Miyagi Prefecture, Pacific coast of northern Japan in 2022, was identified as Photonectes paxtoni Flynn and Klepadlo, 2012, being distinguishable from congeneric species as follows: IV 27–30; VAV 15 or 16 (rarely 13); premaxillary teeth arranged in two rows; pectoral fin absent; dorsal and anal fins not covered by skin, except on bases; barbel short, with a single ovoid bulb without terminal filament and appendages; black pigmented area encircling PTO not reaching below center of eye; IP photophores absent on anterior part of isthmus; last three IP photophores well separated from each other; no luminous patches above gill opening; and blue or white luminous tissues absent on body. Photonectes paxtoni has been previously reported from Papua New Guinea, Micronesia and the Arabian Sea off India, the present specimen representing the northernmost record of the species. The new standard Japanese names “Sazanami-hoteieso” and “Rantan-hoteieso” are proposed for P. cyanogrammicus and P. paxtoni, respectively.

A single specimen of Neobythites macrops (Ophidiidae) (117.2 mm standard length), collected from a depth of ca. 300 m in Suruga Bay, Shizuoka Prefecture, Japan, had the following features: 99 dorsal-fin rays; 83 anal-fin rays; 25 pectoral-fin rays; 2 pelvic-fin rays; 2 preopercular spines; 13 precaudal vertebrae; 45 caudal vertebrae; 58 total vertebrae; 12 gill rakers; 11 scale rows between the dorsal-fin origin and opercular spine tip; 30 scale rows between the anal-fin origin and opercular spine tip; 2 median basibranchial tooth patches; first basibranchial tooth plate rather broad anteriorly; large sulcus only partly separated into colliculi on otolith; pelvic-fin rays not reaching anus; body without horizontal bars or distinct vertical bars; 3 ocelli on dorsal fin; no ocellus on anal fin; posterior third of anal fin blackish. The specimen also exhibited genetic distinctiveness, as analysis of the 12S rRNA region clearly indicates that it is genetically distinct from all Japanese congeners with available sequence data. Neobythites macrops is distributed in the eastern Indian and western Pacific oceans, having been recorded from the Andaman Sea, Philippines, Indonesia, Papua New Guinea, Arafura Sea, and northwestern Australia. The presently reported specimen, described in detail, represents the first record from Japan and northernmost record of the species.

Thirty-seven specimens [37.4–178.4 mm standard length (SL)] of Synodus oculeus Cressey, 1981 (Aulopiformes: Synodontidae), distributed in the Indo-West Pacific region, and previously recorded in Japanese waters from Mago-jima Island (Ogasawara Islands), Yoron-jima Island (Amami Islands), and Okinawa-jima Island (Okinawa Islands), were collected from the Ogasawara Islands (Muko-jima, Ototo-jima, and Chichi-jima islands), Kochi Prefecture, Okinawa Islands (Okinawa-jima, Tokashiki-jima, and Kuro-shima islands), Miyako Islands (Miyako Bank), Yaeyama Islands (Ishigaki-jima and Iriomote-jima islands), and the Senkaku Islands, Japan. With the exception of Okinawa-jima Island, the presently reported specimens, described herein in detail, represent the first records of the species from the above newly-reported localities, a single specimen from Kochi Prefecture being the northernmost record of the species.

A single male specimen of Stiphodon imperiorientis collected from Kochi Prefecture, Shikoku Island, Japan, the northernmost record of the species, was characterized by 15 pectoral-fin soft rays; 9 second dorsal-fin soft rays; 34 longitudinal scales; 11 predorsal scales; 38 tricuspid premaxillary teeth; 12 dusky blotches laterally on body; no white patch laterally behind pectoral-fin base; and small white spots interspersed between black spots on proximal two thirds of pectoral-fin rays. A partial sequence of the COI gene of the specimen closely matched those of S. imperiorientis from Taiwan and China. The specimen may have been transported by the Kuroshio Current from a region south of Kochi Prefecture.

Specimen identifications and field surveys were conducted to determine the distribution of the recently described pike gudgeon Pseudogobio agathonectris Tominaga and Kawase 2019 in Shiga Prefecture. A total of 930 Pseudogobio spp. specimens registered in the Lake Biwa Museum were examined, 40 being identified as P. agathonectris. In addition, field surveys recorded the latter species at five of 20 locations investigated. Compared with the widely distributed congeneric species Pseudogobio esocinus, the distribution of P. agathonectris is limited to the southern part of Shiga Prefecture, south of the Yasu River System.

Spawning of the invasive channel catfish Ictalurus punctatus was investigated in wave-dissipating, stacked boulder areas around restored reed belts in Lake Kasumigaura in late June 2023. Three egg masses (ca. 17–21 cm) were collected by hand from gaps between the boulders. Newly hatched larvae from them were identified as I. punctatus based on a combination of morphological characters, including developed barbels, spherical yolk sac, total length (TL) of 8.8–9.5 mm, myomere counts of 16–18 + 28–29 = 44–47, and absence of melanophores on the body surface. Molecular identification of an egg by mitochondrial cytochrome c oxidase subunit I (COI) gene (655 bp) sequencing corroborated the morphological results, thereby confirming this first record of natural spawning of I. punctatus in Japan. The study suggested that artificial boulder areas in Japanese freshwater lakes may function as spawning grounds.