A. N. Kotlyar

Revision of the genus Poromitra (Melamphaidae): Part 2. New species of the group P. crassiceps

Five new species of the genus Poromitra (family Melamphaidae) belonging to the group of species P. crassiceps are described. An important specific feature of this group is the structure of praeoperculum in which bony crests of the anterior edge are at an acute angle to each other, and the posterior and lower edges are uniformly (without break) spinulated with small spinules. In P. decipiens sp. nova described from the Indian Ocean (from the East Indian Ridge), the insertion of ventral fins is located posteriorly the vertical of the posterior edge of pectoral fin insertion, which makes this species similar to P. crassiceps and P. rugosa. The remaining four species have the insertion of ventral fins anteriorly the vertical (or at its level) of the posterior edge of pectoral fin insertion (as in P. unicornis and P. coronata). P. curilensis sp. nova inhabits the northern part of the Pacific Ocean from the Kuril Islands and the Japanese Islands to the Gulf of Alaska; P. indooceanica sp. nova is described from several individuals from the subtropical part of the Indian Ocean; P. glochidiata sp. nova, from catch in the Great Australian Bight; and P. kukuevi sp. nova, from the individual from the western tropical part of the Atlantic Ocean.

Revision of genus Melamphaes (Melamphaidae): Part 4. Multi-raker species: M. ebelingi, M. occlusus sp. nova, and M. nikolayi sp. nova

In the fourth part of the revision of the genus Melamphaes (Melamphaidae) multi-raker species (20 and more rakers at the first gill arch, rarely 19—in M. ebelingi) with eight soft rays in the ventral fin are considered. In this species, temporal spine is absent, there are 15 rays in the pectoral fin, and there are 11 to 12 abdominal vertebrae. M. ebelingi inhabits tropical and subtropical waters of the Atlantic Ocean. A new catch of this rare species in the northeastern part of the ocean is reported. The new species M. occlusus is described from one specimen from the subtropical part of the southwestern part of the Indian Ocean. Still another new species, M. nikolayi, is described from one specimen from the northwestern part of the Pacific Ocean (subtropical waters). A table for identification of 15 multi-raker species of the genus Melamphaes is provided.

Revision of genus Melamphaes (Melamphaidae). I. Multi-Raker species: M. lugubris, M. xestoachidus sp. nova, M. microps, M. manifestus sp. nova

The taxonomic revision of mesopelagic fish species of Melamphaes genus (Melamphaidae family) was performed on a significant number of specimens. The first part of the paper includes the description of multi-raker species of Melamphaes genus that are characterized by 20 and more rakers on the first gill arch, by seven soft rays in the ventral fin, by the absence of temporal spine, by 16–17 rays in the pectoral fin, and by 12–13 abdominal vestebrae. M. lugubris inhabits the northern Pacific Ocean, in the subarctic and boreal climatic zones. Newly described species, M. xestoachidus, which is similar to M. lugubris, is found in the northwestern Pacific Ocean, eastwards of the Kurils Islands. The species M. microps combines several species. Currently, M. microps species is known by the holotype obtained in the southwestern Indian Ocean and the juvenile caught along the southwestern African coast. The description of new species M. manifestus is performed under six specimens sampled in the equatorial areas of the eastern Atlantic Ocean.

Revision of the genus poromitra (Melamphaidae). Part 4. Species of P.cristiceps Group: P. atlantica, P. oscitans, and P. agofonovae Kotlyar, species nova

Descriptions of three species of poromitras of the P. cristiceps group—P. atlantica, P. oscitans, and P. agafonovae species nova—are provided. The most typical characteristic of this group is the structure of the praeoperculum, in which bony crests of the anterior margin are at an acute angle to each other, and in the posterior angular part there is a typical usually unspined notch. It is shown that P. atlantica, which was reduced in some papers to the synonymy of P. crassiceps, is a valid species. P. atlantica is a circum-Antarctic species that dwells between 30° and 60° S. P. oscitans, which inhabits tropical waters of the Indian and Pacific oceans, is redescribed. The new species P. agafonovae is described from tropical waters of the western part of the Indian Ocean.

Revision of the genus Melamphaes (Melamphaidae): 1. Oligo-Raker species M. laeviceps, M. spinifer, and M. eulepis

The redescription of three oligo-raker species of Melamphaes genus (≤19 rakers on the gill arch)—M. laeviceps, M. spinifer, and M. eulepis—is presented. These species are characterized by eye diameter that is similar or exceeds the width of the suborbital bone. M. laeviceps and M. spinifer inhabit the tropical and subtropical areas of the eastern Pacific Ocean, and M. eulepis inhabits the tropical, mostly equatorial waters of the Atlantic, Indian, and western Pacific oceans.

Revision of genus Melamphaes (Melamphaidae). II. Multi-Raker species: M. polylepis, M. falsidicus sp. nova, M. pachystomus sp. nova, M. macrocephalus, M. leprus

The second part of the publication is devoted to the Melamphaes species (family Melamphaidae), which are characterized by 20 and more rakers on the first gill arch, by seven soft rays in the ventral fin, by absence of a temporal spine, by 14–15 rays in the pectoral fin, and by 11 abdominal vertebrae. M. polylepis is characterized by circumtropical range (Atlantic Ocean, Indian Ocean, western and central Pacific Ocean). Newly described species M. falsidicus is described from the northern Atlantic Ocean, where it was sampled between 34°N and 58°N. Before, this species was defined as M. microps. Another newly described species, M. pachystomus, is described along the Peruvian Coast. M. macrocephalus is redescribed. This species inhabits the eastern tropical Pacific Ocean (approximately between 30°N and 23°S). One of the studied specimens of M. macrocephalus was characterized by larger body size (SL = 128 mm) than was described before for this species. M. leprus is known currently by single findings from the eastern tropical Atlantic Ocean (between 11°N and 4°S). This species was also found in the samples obtain in the Gulf of Guinea.

Revision of the genus Poromitra (Melamphaidae): Part 6. Species of the P. megalops group

Species of the genus Poromitra belonging to the P. megalops group are considered on a large collection material. These species are characterized by small sizes (up to 6 cm), oblong body, elongated caudal peduncle, large eyes, four scales on the cheek, bony crests of the anterior margin of the praeoperculum located at a right angle towards each other, and other features. Until recently it was considered that P. megalops (Lütken) has a circumtropical range. This study demonstrated that P. megalops occurs only in the Atlantic Ocean. In the Indian Ocean and the central part of the Pacific Ocean, P. macrophthalma (Gilchrist) dwells. A new species P. jucunda Kotlyar sp. nova is described from the eastern and central parts of the Pacific Ocean. A key to 22 known species of the genus Poromitra is provided at the end of the paper.

Revision of the genus Melamphaes (Melamphaidae): Part 3. Multirakered species: M. suborbitalis, M. parini, and M. acanthomus

In the third part of the revision of the genus Melamphaes Melamphaidae (Melamphaidae), we examine multirakered species (20 and more rakers at the first gill arch) with seven soft rays in the ventral fin that have a posttemporal (temporal) spine directed anteriorly-upwards, with 14–15 rays in the pectoral fin, and 11 (rarely 12) trunk vertebrae. M. suborbitalis inhabits the Atlantic Ocean (in the north up to 57°N, in the south, up to 40°S), the Indian Ocean (is known in its southwestern part), and the western part of the Pacific Ocean. There is no significant evidence on catches of this species in the eastern part of the Pacific Ocean. Apparently, M. suborbitalis is absent in the tropical waters of the oceans. Until recently, M. parini was known from the holotype caught in the Sea of Okhotsk. Two specimens of this rare species: from the central (the area of the Hawaiian Islands) and the northeastern part of the Pacific Ocean are reported. M. acanthomus is an endemic of the eastern part of the Pacific Ocean where it is known along the coasts of America from California to the northern coast of Chile (approximately between 33°N and 21°S).

Revision of the genus Melamphaes (Melamphaidae): 2. Oligo-Raker species: M. longivelis Parr, M. inconspicuus sp. n., M. kobylyanskyi sp. n.

Redescription of the Melamphaes longivelis is presented. Two new species related to it are described: M. inconspicuus sp. n. and M. kobylyanskyi sp. n. M. longivelis inhabits the northern part of the Atlantic Ocean, from the equatorial waters up to 50° N; the species has not been confirmed to occur in the Southern Atlantic. M. inconspicuus is described from the tropical waters of the Northern Atlantic, while M. kobylyanskyi from the Walvis Ridge of the Southeastern Atlantic.

Revision of the genus Poromitra (Melamphaidae): Part 5. Species of groups P. capito and P. crassa

Species of the genus Poromitra that belong to groups P. capito and P. crassa are considered. The most typical character of the group P. capito is the structure of the praeoperculum, in which bony crests of the anterior margin are at a right angle to each other, and an increased spine is located in the corner of the praeoperculum. The group consists of two species: P. capito and P. gibbsi. It has been established that P. capito inhabits the northern and tropical parts of the Atlantic Ocean and also, possibly, the southwestern Atlantic. The indication of the occurrence of this species in the southern part of the Pacific Ocean (Ebeling, 1975) should be referred to P. gibbsi. Until recently it was considered that P. gibbsi inhabits only the southeastern part of the Pacific Ocean. This study indicates that this species inhabits the entire southern Pacific from the coasts of South America to New Zealand (between the equator and 35° S). The description of P. crassa—a single species of the group with the same name—has been specified. In this species, bony crests of the anterior margin of the praeoperculum are approximately at a right angle, the lower and posterior margins of the bone are uniformly spinulated, and there is no increased spine in the angle. The species is known from single captures in the area to the north of New Guinea.