Redescription and first Japanese seamount record of Stethopristes eos (Zeiformes; Parazenidae).

During a biodiversity survey conducted in 2020, focusing on seamounts located in the southern region of Japan, specifically designated as marine protected areas, a single specimen of Stethopristes eos Gilbert, 1905 measuring 124.2 mm in standard length was obtained via the use of a remotely operated vehicle (ROV). The collection occurred at a depth of 519 meters on the Ritto Seamount, located along the western Mariana Ridge. However, this species is poorly known, with only a limited dataset available concerning its morphology. In this study, we present a comprehensive redescription of the species, utilizing information obtained from the type specimens and a newly discovered specimen from Japanese waters. The Japanese specimen constitutes the first recorded occurrence of this species within the western Pacific Ocean. As part of this redescription, we suggest new standard Japanese names for both the genus and species.

Resurrection and redescriptions of nominal species previously regarded as synonyms of Thrissina mystax (Bloch and Schneider, 1801) (Teleostei: Clupeiformes: Engraulidae).

Examination of the original descriptions and available type specimens of nominal species previously regarded as synonyms of Thrissina mystax (Bloch and Schneider, 1801), and many non-type specimens representing an extensive geographic range, confirmed the validities of T. mystax, Thrissina porava (Bleeker, 1849), and Thrissina valenciennesi (Bleeker, 1866). Additionally, Engraulis poorawah Bleeker, 1872, a nominal species previously regarded as a junior synonym of T. mystax, is recognized as a junior synonym of Thrissina malabarica (Bloch, 1795). Diagnoses and detailed color descriptions are given for all of the valid species, in addition to clarification of their taxonomic histories, and neotype designation for T. porava. The phylogenetic relationships among 15 species of Thrissina (including T. porava and T. valenciennesi but not T. mystax) were reconstructed from the mitochondrial cytochrome oxidase I (COI) gene. T. porava and T. valenciennesi were not recovered as a monophyletic group, instead being divergent from each other and the other species of Thrissina by 12.4% and >11.7% mean uncorrected distances, respectively, confirming their reciprocal validity.

Stolephorus lotus, a New Anchovy (Teleostei: Clupeiformes: Engraulidae) from the Northern Territory, Australia.

A new anchovy Stolephorus lotus sp. nov., is described based on 30 specimens collected from Van Diemen Gulf, Northern Territory, Australia. The species closely resembles Stolephorus acinaces Hata, Lavoué and Motomura, 2020 and Stolephorus andhraensis Babu Rao, 1966, in having a long maxilla (posterior tip just reaching or extending slightly beyond the posterior margin of the opercle), indented posterior preopercular margin, anal fin with 16-18 branched fin rays, and 21-23 lower gill rakers, and lacking a predorsal scute and pelvic scute spine. However, the new species differs from the other two species in having higher counts of longitudinal series of scale rows and predorsal scales (37-39 and 20 or 21, respectively vs. 35-38 and 17-19 in the other two) and a more anteriorly located anal-fin origin (below bases of sixth to eighth dorsal-fin rays vs. eighth to tenth dorsal-fin rays).

A New Species of the Bengal Spined Anchovy Stolephorus from the Eastern Indian Ocean and Redescription of Stolephorus dubiosus Wongratana, 1983, with Comments on the Evolution of Prepelvic Scute Numbers within Stolephorus (Clupeiformes: Engraulidae).

The Bengal Spined Anchovy, Stolephorus taurus sp. nov. is described from 21 specimens from the northern Bay of Bengal. The new species closely resembles Stolephorus dubiosus Wongratana, 1983, which is redescribed. Both species have a predorsal scute, spine on the pelvic scute, long maxilla posteriorly slightly short of or just reaching the posterior margin of the opercle, 25 or more gill rakers on the lower limb of the first gill arch, and double black lines on the dorsum posterior to the dorsal fin. However, the new species differs from S. dubiosus in having a longer pelvic fin with the posterior tip of the depressed fin beyond vertical through the dorsal-fin origin (vs. usually not reaching to vertical through dorsal-fin origin), longer pectoral fin, second dorsal-and third dorsal-fin rays, second anal-and third anal-fin rays, and greater interorbital width. Stolephorus taurus sp. nov. is closely related to Stolephorus baganensis Delsman, 1931 and S. dubiosus, although at least 2% mean p-distance divergence in the mitochondrial cytochrome c oxidase subunit I (COI) gene separates each of the three species. A phylogenetic reconstruction of the evolution of the number of prepelvic scutes within Stolephorus indicated that having six scutes was the most likely ancestral condition in the genus, and was later reduced in the evolution of Stolephorus to five or four scutes. One such reduction occurred recently in the lineage of Stolephorus taurus sp. nov.

Description of three new species previously identified as Stolephorusbengalensis (Dutt & Babu Rao, 1959) or Stolephorusinsularis Hardenberg, 1933 and a re-description of S.bengalensis (Chordata, Osteichthyes, Clupeiformes, Engraulidae).

Examination of numerous specimens characterised by predorsal scute, long maxilla, indented preopercle and pelvic scute lacking a spine and previously identified as Stolephorusbengalensis (Dutt & Babu Rao, 1959) or Stolephorusinsularis Hardenberg, 1933, revealed four distinct species, true S.bengalensis (distributed from the Bay of Bengal to Pakistan) and three new species, viz., Stolephoruseldorado sp. nov. (Taiwan to Java, Indonesia), Stolephorusdiabolus sp. nov. (Strait of Malacca, from Penang , Malaysia, to Singapore) and Stolephoruseclipsis sp. nov. (Bintan Island, Riau Archipelago, Indonesia). Characters separating the four species include numbers of gill rakers on each gill arch and vertebrae and pelvic fin and dorsal-fin ray lengths. Two molecular markers (mitochondrial cytochrome b and cytochrome oxidase I genes) demonstrated the distinction of three of the species examined morphologically and enabled a reconstruction of their phylogenetic relationships. Each species was genetically divergent from the others by 3.5%-7.7% mean uncorrected distance in the mitochondrial cytochrome oxidase I gene.

Stolephorus grandis, a new anchovy (Teleostei: Clupeiformes: Engraulidae) from New Guinea and Australia.

The new anchovy Stolephorus grandis n. sp., described on the basis of 10 specimens collected from Papua, Indonesia, and Australia, closely resembles Stolephorus mercurius Hata, Lavou Motomura, 2021, Stolephorus multibranchus Wongratana, 1987, and Stolephorus rex Jordan Seale, 1926, all having double pigmented lines on the dorsum from the occiput to the dorsal-fin origin, a long maxilla (posterior tip just reaching or slightly beyond the posterior margin of preopercle), and lacking a predorsal scute. However, the new species clearly differs from the others in having fewer gill rakers (3539 total gill rakers on the first gill arch in S. grandis vs. > 38 in the other species), a greater number of vertebrae (total vertebrae 4243 vs. fewer than 41), longer caudal peduncle (21.923.7% SL vs. 20.8%), and the depressed pelvic fin not reaching posteriorly to vertical through the dorsal fin-origin (vs. reaching beyond level of dorsal-fin origin).

Sardinella ventura n. sp. (Actinopterygii: Clupeiformes: Clupeidae), a new sardine from Mauritius.

The new sardine Sardinella ventura n. sp. (Teleostei: Clupeiformes: Clupeidae) is described on the basis of 10 specimens collected from Mauritius. The new species is most similar to Sardinella dayi Regan 1917 in having non-deciduous scales with pores and discontinuous striae, a dark spot on the dorsal-fin origin, the pelvic fin with 8 rays, and similar number of gill rakers, in addition to very similar numbers of keeled scutes. However, the new species is distinguished from S. dayi by having a shorter caudal peduncle [6.27.6% SL (mean 7.0%) vs. 8.212.0% (9.2%) in S. dayi], larger eye [8.49.9% (9.0%) vs. 6.88.0% (7.4%)] and orbit [9.612.3% (10.7%) vs. 8.510.2% (9.3%)], longer pectoral [21.022.7% (21.5%) vs. 17.021.0% (19.8%)] and pelvic fins [12.513.5% (12.8%) vs. 10.412.2% (11.2%)], and a greater numbers of pseudobranchial filaments [1719 (modally 17) vs. 1822 (19)], lateral scale rows in longitudinal series [4143 (41) vs. 3842 (40)] and transverse scales [11 or 12 (12) vs. 11]. There were significant differences in seven meristic and 14 morphometric characters between the two species.

A New Species of the Anchovy Genus Stolephorus Lacepède 1803 from North Sumatra, Indonesia, and Redescriptions of Stolephorus pacificus Baldwin 1984 and Stolephorus teguhi Kimura, Hori and Shibukawa 2009 (Teleostei: Clupeiformes: Engraulidae).

Stolephorus leopardus sp. nov. is described here, and Stolephorus pacificus and Stolephorus teguhi are redescribed. Those three species are distinguished among congeners by the presence of more than 30 gill rakers on the lower limb of the first gill arch and a short maxilla, posteriorly just reaching the anterior border of the preopercle. Stolephorus pacificus and S. teguhi have rarely been reported since they were originally described, and therefore detailed morphological data and further diagnostic characters are provided. Stolephorus leopardus, in turn, is described based on four specimens collected on Nias Island, North Sumatra Province, Indonesia. The new species can be distinguished from S. pacificus and S. teguhi by a shorter pectoral fin (15.6-16.3% of standard length vs. longer than 16.5%), a longer snout (4.7-4.8% of standard length vs. < 4.5%), and an intermediate number of total gill rakers on the first gill arch (63-68 in S. leopardus vs. 57-63 in S. pacificus and 72-82 in S. teguhi). In addition, the new species differs from S. pacificus in having a dark line on the dorsum (vs. line absent), numerous melanophores laterally on the head (vs. a few melanophores on the snout and mandible tips), and higher counts of branched anal-fin rays [19-21(modally 19) vs. 17-19 (18)]. Stolephorus leopardus is further distinguished from S. teguhi by a shorter anal-fin base (22.4-22.5% of standard length vs. 22.7-25.3%).

Stolephorus babarani, a new species of anchovy (Teleostei: Clupeiformes: Engraulidae) from Panay Island, central Philippines.

The new anchovy Stolephorus babarani n. sp. is described on the basis of 26 specimens collected from Panay Island, central Philippines. The new species closely resembles Stolephorus bataviensis Hardenberg 1933 and Stolephorus baweanensis Hardenberg 1933, all these species having a long upper jaw (posterior tip extending beyond posterior margin of preopercle), and numerous dusky spots on the suborbital area (in adults), snout and lower jaw tip. However, the new species differs from S. bataviensis by usually having the posterior tip of the depressed pelvic fin not reaching to vertical through the dorsal-fin origin (vs. extending beyond vertical through dorsal-fin origin), a shorter head (23.9-25.5% of standard length vs. 25.3-28.0%), and a greater distance between the dorsal-fin origin and pectoral-fin insertion (D-P1; 133.9-151.8% of head length vs. 109.9-136.3%). Stolephorus babarani is distinguished from S. baweanensis by having a shorter snout (3.6-3.9% of standard length vs. 3.8-4.6%). Moreover, the new species can be distinguished from S. bataviensis and S. baweanensis by higher gill raker counts on the first and second gill arches (16-18 + 21-23 and 10-13 + 18-21, respectively, vs. 14-17 + 19-22 and 9-12 + 17-20 in S. bataviensis and 14-17 + 19-22 and 9-12 + 17-21 in S. baweanensis). Stolephorus babarani is separated by 5.3% and 10.7% mean p-distances in the mitochondrial COI from S. baweanensis and S. bataviensis, respectively.

A new species of anchovy, Encrasicholina sigma (Teleostei, Clupeiformes, Engraulidae), from Sulawesi, Indonesia.

The new anchovy Encrasicholina sigma n. sp. is described on the basis of 20 specimens collected from Sulawesi, Indonesia. Although the new species can be distinguished from all other congeners except for Encrasicholina pseudoheteroloba (Hardenberg 1933) by having a long upper jaw reaching to posterior margin of preopercle, dorsal and anal fins with two unbranched rays, an exposed bony urohyal, and spine-like scutes on the abdomen, E. sigma is distinguished from E. pseudoheteroloba by lower total gill-raker counts on the first, second, third, and fourth gill arches, and on the posterior face of the third gill arch (37-42, 31-35, 18-23, 16-20, and 4-7, respectively vs. 45-55, 34-45, 22-29, 19-25, and 4-9 in E. pseudoheteroloba) and a longer head (25.2-27.0% of SL vs. 22.8-27.5%) and shorter anal-fin base (12.9-14.8% of SL vs. 13.8-18.7%).

A new species of sardine, Sardinella electra (Teleostei: Clupeiformes: Clupeidae), from the Ryukyu Islands, Japan.

A new species of sardine, Sardinella electra, is described on the basis of 18 specimens collected from the Ryukyu Islands, Japan. The new species closely resembles Sardinella hualiensis (Chu Tsai 1958) in that both species have a caudal fin with black tips, a black spot on the dorsal-fin origin, and both have lateral scales with centrally continuous or overlapping longitudinal striae. However, the new species is distinguished from S. hualiensis by its higher total gill-raker counts on the first, second, third and fourth gill arches, and on the posterior face of the third gill arch (105-121, 107-120, 88-104, 65-82, and 25-31, respectively, vs. 87-107, 83-105, 67-90, 53-69, and 13-27), and in having scales with few perforations and lacking pores posteriorly (vs. scales with numerous perforations and pores on their posterior margins).

A new species of sardine, Sardinellapacifica from the Philippines (Teleostei, Clupeiformes, Clupeidae).

A new sardine, Sardinellapacifica sp. n., is described on the basis of 21 specimens collected from the Philippines. The new species closely resembles Sardinellafimbriata (Valenciennes, 1847), both species having lateral scales with centrally discontinuous striae, a dark spot on the dorsal-fin origin, more than 70 lower gill rakers on the first gill arch, the pelvic fin with eight rays, and 17 or 18 prepelvic and 12 or 13 postpelvic scutes. However, the new species is distinguished from the latter by lower counts of lateral scales, pseudobranchial filaments, and postpelvic scutes (38-41, 14-19 and 12-13, respectively vs. 44-46, 19-22 and 13-14), and a shorter lower jaw (10.4-11.6% of standard length vs. 11.1-12.2%). Sardinellapacifica sp. n. is known only from the Philippines, whereas S.fimbriata is restricted to the Indian Ocean, although previously considered to be an Indo-West Pacific species, distributed from India to the Philippines.

Sardinella alcyone n. sp., a new sardine (Teleostei: Clupeiformes: Clupeidae) from the northwestern Pacific Ocean.

The new sardine Sardinella alcyone n. sp. is described on the basis of 19 specimens collected from the Ryukyu Islands, Japan and southwestern Taiwan. The new species closely resembles Sardinella pacifica Hata Motomura 2019, both species having lateral scales with centrally discontinuous striae, a dark spot on the dorsal-fin origin, the pelvic fin with 8 rays, deciduous body scales, and very similar numbers of prepelvic and postpelvic scutes, scale rows in the longitudinal series, and pseudobranchial filaments. However, the new species is distinguished from S. pacifica by having lower total gill-raker counts on the first, second, third and fourth gill arches, and on the posterior face of the third gill arch (99-112, 97-115, 79-98, 62-77, and 25-31, respectively, vs. 112-137, 112-148, 95-127, 78-106, and 30-43), and greater pectoral fin (20.7-23.4% SL vs. 18.2-20.8%), pelvic fin (11.9-13.1% SL vs. 10.3-11.9%), maxilla (10.8-12.4% SL vs. 9.3-10.9%), lower jaw (11.8-13.4% SL vs. 10.4-11.6%), and pre-anal-fin length (77.4-82.3% SL vs. 72.9-79.3%) proportions.

Review of the fish genus Epinnula Poey (Perciformes: Gempylidae), with description of a new species from the Pacific Ocean.

The gempylid fish genus Epinnula is reviewed and two species are recognized. The type species E. magistralis is considered restricted to the western Atlantic Ocean and a new species from the Pacific Ocean is described. The new species, Epinnula pacifica sp. nov., can be distinguished from E. magistralis by 17 or 18 dorsal-fin rays (vs. 15 or 16 in E. magistralis), 15 or 16 anal-fin rays (vs. 13 or 14), 247-268 total scales on lower lateral line (vs. 285-330), a deeper body, relatively high dorsal fin as reflected by the relatively long fin spines and rays, longer dorsal-fin and anal-fin bases, longer pectoral fin, and longer pelvic fin and pelvic spine.

Molecular systematics of the anchovy genus Encrasicholina in the Northwest Pacific.

The anchovy genus Encrasicholina is an important coastal marine resource of the tropical Indo-West Pacific (IWP) region for which insufficient comparative data are available to evaluate the effects of current exploitation levels on the sustainability of its species and populations. Encrasicholina currently comprises nine valid species that are morphologically very similar. Only three, Encrasicholina punctifer, E. heteroloba, and E. pseudoheteroloba, occur in the Northwest Pacific subregion of the northeastern part of the IWP region. These species are otherwise broadly distributed and abundant in the IWP region, making them the most important anchovy species for local fisheries. In this study, we reconstructed the phylogeny of these three species of Encrasicholina within the Engraulidae. We sequenced 10 complete mitochondrial genomes (using high-throughput and Sanger DNA sequencing technologies) and compared those sequences to 21 previously published mitochondrial genomes from various engraulid taxa. The phylogenetic results showed that the genus Encrasicholina is monophyletic, and it is the sister group to the more-diverse "New World anchovy" clade. The mitogenome-based dating results indicated that the crown group Encrasicholina originated about 33.7 million years ago (nearby the limit Eocene/Oligocene), and each species of Encrasicholina has been reproductively isolated from the others for more than 20 million years, despite their morphological similarities. In contrast, preliminary population genetic analyses across the Northwest Pacific region using four mitogenomic sequences revealed very low levels of genetic differentiation within Encrasicholina punctifer. These molecular results combined with recent taxonomic revisions are important for designing further studies on the population structure and phylogeography of these anchovies.

A new species of anchovy, Encrasicholina macrocephala (Clupeiformes: Engraulidae), from the northwestern Indian Ocean.

A new species of anchovy, Encrasicholina macrocephala, is described on the basis of 17 specimens collected from the Red Sea and the Arabian Sea. The species is closely related to E. devisi in that both species have three unbranched rays in the dorsal and anal fins, and a long upper jaw (posterior tip extending beyond posterior margin of preopercle). However, the new species is distinguished from E. devisi in having lower counts of total pectoral-fin rays (11-14 vs. 13-15) and pseudobranchial filaments (15-18 vs. 18-22), longer head length (29.5-31.7% of standard length vs. 25.4-28.9% in the latter), upper-jaw length (21.3-23.5% vs. 14.6-21.3%), and lower-jaw length (19.5-21.2% vs. 14.2-19.5%), and a shorter distance between the dorsal-fin origin to the pectoral-fin insertion (83.2-95.2% of head length vs. 97.6-126.1%).