Rypticus africanus: A new species of Soapfish from the eastern Atlantic.

Soapfish, Grammistes and Rypticus spp., are bottom-dwelling Perciform Fish related to Groupers, generally found on reefs and other rocky marine environments. They get their common name from their ability to secrete a toxic, soapy, mucus as a defence mechanism. The genus Grammistes is restricted to the Indo-Pacific region, while members of the genus Rypticus are found in the Western Pacific, Atlantic and Caribbean. Only two species of Rypticus have been found on the African coast, the Greater Soapfish, Rypticus saponaceus, and the Spotted Soapfish, Rypticus subbifrenatus. The Greater Soapfish is known from both sides of the Atlantic being found from the coast of Florida, throughout the Caribbean, and as far south as Brazil in the western Atlantic, and from Mauritania south as far as Angola in the eastern Atlantic. However, a genetic study of museum specimens published in 2003 suggested that the eastern and western populations of the Greater Soapfish might in fact be separate species.

In a paper published in the Journal of Fish Biology on 21 July 2025, Gabriel Soares Araujo of the Center for Marine Biology at the University of São Paulo, Cláudio Sampaio of the Laboratório de Ictiologia e Conservação at the Universidade Federal de Alagoas, Luiz Rocha of the  Department of Ichthyology at the California Academy of Sciences, and Carlos Eduardo Ferreira Leite of the Departamento de Biologia Marinha at the Universidade Federal Fluminense, re-examine the genetics of the Greater Soapfish, and formally describe the populations from the African coast as a separate species.

Araujo et al. examined specimens from Cape Verde, Ghana, São Tomé and Príncipe, and Togo. All were found to be genetically distinct from western Atlantic specimens of Rypticus saponaceus, forming a distinct population which is estimated to have split from the west Atlantic population in the Early Pleistocene, about 2.5 million years ago, at the onset of the Pleistocene, and surprisingly being more closely related to the Pacific Rypticus bicolor. Since Rypticus saponaceus was originally described from specimens from Florida, the east Atlantic population is described as a new species, which Araujo et al. name Rypticus africanus.

Time-calibrated phylogeny of the genus Rypticus based on mitochondrial COI gene sequences. Values near the nodes represent estimated divergence times (Mya). The 95% highest posterior density intervals are shown in parentheses. Coloured circles represent the biogeographic regions where species of Rypticus are distributed. Vertical bars depict the results of lineage delimitation tests. Araujo et al. (2025).

Specimens of Rypticus africanus examined range from 112 to 215 mm in length, and have three dorsal fin spines, 22-24 dorsal fin rays, 15-17 anal fin rays, 16-18 pectoral fin rays, and 24-25 caudal (tail) fin rays. The head is distinctly pointed, the dorsal fin originates slightly posterior to upper end the of gill opening, and the tail is rounded. They are brown or dark grey in colour, with numerous pale round spots of variable size on their flanks.

(a)–(c) Rypticus africanus from São Tomé and Príncipe, illustrating the variation in colour pattern between individuals: (a) São Tomé Island, (b), (c) Príncipe Island and (d) Rypticus saponaceus from Salvador, Bahia, Brazil, shown for comparison. Araujo et al. (2025).

Although Rypticus africanus has only been sampled from four areas (Cape Verde, Ghana, São Tomé and Príncipe, and Togo), Araujo et al. believe the name should be applied to all African populations currently described as Rypticus saponaceus, from Mauritania to Angola.

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Plectranthias raki: A new species of Perchlet from the Maldives.

The term 'Perchlet' applies to a wide variety of small Perciform Fish. The genus Plectranthias is a member of the Serranidae, the family which also includes Sea Bass and Groupers, amongst other groups. It currently contains 66 described species from mesophotic reef environments in the Atlantic, Pacific, and Indian Oceans. Plectranthias are small Fish, typically 5-10 cm long with the largest species reaching about 20 cm, which live in holes or crevices, from where they ambush small, mobile invertebrates. The small size and cryptic nature of Plectranthias means that they are not well studied, with most species described from a very small number of specimens.

In a paper published in the journal ZooKeys on 16 January 2024, Bart Shepherd of the Steinhart Aquarium at the California Academy of Sciences, Hudson Pinheiro of the Department of Ichthyology at the California Academy of Sciences, and the Center for Marine Biology at the University of São Paulo, Ahmed Najeeb, also of the Department of Ichthyology at the California Academy of Sciences, and of the Maldives Marine Research Institute, Claudia Rocha, again of the Department of Ichthyology and of the Department of Microbiology at the California Academy of Sciences, and Luiz Rocha, once again of the Department of Ichthyology at the California Academy of Sciences, describe a new species of Plectranthias from the Kuramathi Outer Reef on Rasdhoo Atoll in the Maldives.

The new species is described from two specimens collected by hand-netting at a depth of 118 m, in December 2022, and confirmed as a new species by gene-sequencing. It is named Plectranthias raki, where 'raki' means 'feeling shy to confront people' in the Dhivehi language which is spoken in the Maldives.

Living specimen (not retained) of Plectranthias raki photographed at 110 m depth at Dhaalu Atoll, Maldives. Luiz Rocha in Shepherd et al.  (2025).

The two specimens of Plectranthias raki are 66.15 and 70.41 mm long, and pinkish white in colour with a series of irregular orange-red patches, these being more red towards the tail and more yellow towards the head. Both have dorsal fins with fifteen rays, anal fins with seven rays, pectoral fins with thirteen rays, and tail fins with nine upper rays and eight lower rays.

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Sueviota aethon: A new species of Dwarf Gobi from the Red Sea coast of Saudi Arabia.

First described in 1988, the Dwarf Gobi genus Sueviota is distinguished from the closely related Eviota on the structure of its pelvic fins. The genus currently contains eight species, found from Papua New Guinea and the northwestern coast of Australia through to the Red Sea.

In a paper published in the journal ZooKeys on 12 September 2024, Viktor Nunes Peinemann and Lucía Pombo-Ayora of the Red Sea Research Center of King Abdullah University of Science and Technology, Luke Tornabene of the School of Aquatic and Fishery Sciences and Burke Museum of Natural History and Culture of the University of Washington, and Michael Berumen, also of the Red Sea Research Center of King Abdullah University of Science and Technology, describe a new species of Sueviota from the Red Sea coast of Saudi Arabia.

The new species is named Sueviota aethon, where 'aethon' derives from Aethon, one of the four Horses which drew the chariot of the Sun God Helios in Greek mythology; it is so named due to its similarity to the previously described Sueviota pyrios; Pyrios having been another of the four Horses. The species is described from ten specimens collected from exposed offshore reefs on the Saudi Arabian Red Sea coast, at depths of between 10 m and 30 m, although Nunes Peinemann et al. note that another specimen was observed at a depth of 53 m.

Holotype specimen of Sueviota aethon (UW 203365), shortly after being collected. Nunes Peinemann et al. (2024).

Specimens of Sueviota aethon are between 9.2 mm and 16.7 mm in length, and most known specimens are dark red in colour (one was a yellow-orange colour). The first dorsal fin is rounded-to-square in shape, with the second and third spines longer than the first. The rays of the second dorsal fin are commonly branched (at least some of these are branched in all known specimens). The body is covered by ctenoid (comb-edged) scales, but these are absent from the head and breast. Two rows of irregularly spaced conical teeth are present on both the lower and upper jaws. Both jaws also have enlarged canine teeth, with these forming part of the outer tooth-row in the upper jaw and the inner tooth-row in the lower jaw.

Micro-CT scan of Sueviota aethon (UW 203365, holotype) showing its osteological characters. (a) Close-up of head showing the enlarged canines on the upper jaw, (b) dentary, showcasing two enlarged canines in the internal row of teeth, (c) lateral view of the complete skeleton. Nunes Peinemann et al. (2024).

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Unknown Snailfish sighted 8336 m beneath the surface is the deepest Fish ever recorded.

A team of Japanese and Australian scientists exploring the Izu-Ogasawara Trench, south of Japan, by Remote Operated Vehicle, has spotted an unknown species of Snailfish, Pseudoliparis sp., living at a depth of 8336 m, making it the deepest Fish ever recorded. This exceeds the previous record by 158 m, another Snailfish caught in a trap within the Japan Trench in 2017. A few days later the same team was able to trap two species of Belyaev's Snailfish, Pseudoliparis belyaevi, at a depth of 8022 m. Belyaev's Snailfish is an exclusively deep water species, having never been encountered at depths shallower than 7703 m.

Unknown Snailfish, Pseudoliparis sp., sighted at a depth of 8336 m in the Izu-Ogasawara Trench, south of Japan. University of Western Australia.

The team, led by Alan Jamieson of the University of Western Australia, have been exploring the Izu-Ogasawara and Japan trenches for 15 years, finding a surprising number of Fish at depths in excess of 8000 m. Previous exploration of the mush deeper Mariana Trench has found very few Fish at these depths. The majority of these Fish are Snailfish, a group uniquely suited to surviving at such great depths. Snailfish lack swim-bladders and scales, have a very lightly calcified skeleton, and protect themselves with a layer of mucus, which gives them their name. Living at these depths they have very few natural predators, although food is also very scarce, largely comprising of carrion which has sunk from higher in the water column.

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Pagrus major: A Red Seabream from the Late Pleistocene of Taiwan.

Although the island of Taiwan has been extensively studied by geologists interested in its tectonic structure, it has been largely overlooked by palaeontologists. This is unfortunate, as the subduction of the South China Sea basin beneath the Philippine Sea Plate here has created an accretionary wedge on the Hengchun Peninsula on the south of the island that records the evolving marine faunas of the South China Sea biodiversity hotspot the Late Pleistocene.

In a paper published in the journal Zoological Studies on 5 May 2022, Chien-Hsiang Lin of the Biodiversity Research Center of Academia Sinica, Hsin-Yueh Ou of the Department of Life Science at Tunghai University, Chia-Yen Lin, also of the Biodiversity Research Center of Academia Sinica, and Hong-Ming Chen of the Department of Aquaculture at the National Taiwan Ocean University, describe a fossil Fish from a concretion assigned to the Late Pleistocene Szekou Formation of the Hengchun Peninsula.

The specimen comes from a sandstone block collected some decades ago by amateur collectors, and donated to the Biodiversity Research Museum at Academia Sinica by Cheng-Kai Chiang. Only half of the block is present, exposing a Fish skeleton, and this appears does not appear to have been broken open by Human intervention, making it likely that the counterpart was never found. Although the exact point of origin of the fossil is unknown, its collectors did record where it was found, and a visit to this site suggests that the Szekou Formation is the only lithological unit here which matches the rock type of the specimen. Since nodules from the Szekou Formation have produced a variety of other Late Pleistocene Fish, Crustaceans, and Molluscs, this does not seem an unreasonable assumption.

Pagrus major, ASIZF0100141, from the Late Pleistocene Szekou Formation, Hengchun Peninsula, southern Taiwan. (A) Lateral view of the nodule. (B) Dorsal view of the anterior part of the nodule, note that fragments of the right jaws are exposed. (C) Drawing of the recognised skull parts. Abbreviations: al.p.pm, alveolar process of the premaxilla; An, angular. ar.p.pm, articular process of the premaxilla; as.p.pm, ascending process of the premaxilla; Art, articular; Brr, branchiostegal ray; can., caniniform teeth; Ce, ceratohyal. con., conical teeth; cp, coronoid process of dentary; cr.s, superior crest on the articular; Den, dentary; d.p.art, descending process of the articular; Enp, endopterygoid; Ino, interoperculum; mdc, dorsal crest on maxilla; mol., molariform teeth; Mpt, metapterygoid; Mx, maxilla; Op, opercle; Pl, palatine; Pmx, premaxilla; Pop, preopercle; Q, quadrate; Sop, subopercle. Lin et al. (2022).

Exposed on the nodule are an almost complete lower part (splanchnocranium) of a left skull, plus a fragmentary right premaxilla and dentary, and the anterior part of the body, largely covered by scale fragments. Fragments of the coracoid and cleithrum are visible just behind the opercle. 

Based upon examination of the teeth and maxilla, the remains can clearly be assigned to the Family Sparidae (Seabream). It can further be excluded from the genus Dentex by the presence of molariform teeth (which Dentex lacks). The specimen has villiform teeth along the proximal ring of its jaws, which suggests that it belongs to the genera Pagrus, Chrysophrys, or Evynnis. Furthermore, the specimen has large anterior caniform teeth, which would appear to rule out membership of the genus Evynnis. 

The genera Pagrus and Chrysophrys each contain a single species; the Red Seabream, Pagrus major and the Australasian Snapper, Chrysophrys auratus. These species can only be differentiated morphologically by the presence of a bump on the supraoccipital bone (forehead) of Chrysophrys auratus. It has been suggested that these are in fact different populations of the same species, but recent genetic analysis has revealed that they are separate species, with their most recent common ancestor probably living in the Pliocene or Early Pleistocene. The two species are now often considered to be members of the same species.

Today, Pagrus major is found in the western Pacific, around the coasts of Japan, South China, Taiwan and the Philippines, whereas Chrysophrys auratus is found further east, around the coasts of Australia, New Zealand, and the islands of the South Pacific. However, it does not automatically follow that either species would have had the same distribution in the Pleistocene, when the distribution of climate bands was quite different.

The specimen from the Szekou Formation lacks any sign of a supraoccipital bump, which leads Lin et al. to conclude that it is a specimen of Pagrus major, and that therefore this species was present in the waters around Taiwan in the Late Pleistocene.

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Sillago muktijoddhai & Sillago mengjialensis: Two new species of Sillago from Bangladesh.

Sillagos, Sillago spp., are inshore Perciform Fish widespread in the IndoPacific region. They form an important part of many food webs, feeding on Crustaceans and Molluscs in coastal waters or estuarine areas of rivers with open sandflats and muddy substrates, and in turn being fed upon by larger Fish, Marine Mammals, and Seabirds. Understanding the population structure of these Fish has proven difficult, as the genus contains a large number of very similar-appearing species, often identifiable only by the structure of their swim bladders, with the recent application of genetic profiling to the group suggesting that even this is not reliable, and that the group may contain more cryptic species (species which cannot easily be told apart by physical examination) than previously realised.

In a paper published in the journal Fishes on 18 April 2022, Shilpi Saha of the Fisheries College at the Ocean University of China, and the Department of Zoology at Jagannath University, Na Song and Zhengsen Yu, also of the Fisheries College at the Ocean University of China, Mohammad Abdul Baki, also of the Department of Zoology at Jagannath University, Roland McKay of the Chillagoe Museum, Jianguang Qin of the School of Biological Sciences at Flinders University, and Tianxiang Gao of the Fishery College at the Zhejiang Ocean University, describe two new species of Sillago from Bangladesh.

The new species are described from specimens obtained from fishermen at locations in Cox’s Bazar, Sundarbans, Patharghata, Maheshkhali and Saint Martin’s Island. These Fish are typically caught using beach seine nets in this area.

The first new species described is named Sillago muktijoddhai, were 'muktijoddhai' refers to the muktijoddha freedom fighters who fought for Bangladesh's independence from Pakistan from 1971 to 1979. 

Sillago muktijoddhai is elongated in shape, slightly steep anteriorly, and tubular posteriorly. The upper jaw is slightly protracted and crescentic, with minute villiform teeth on both jaws in one row. The back edge of the preopercle is slightly denticulated, and the opercle has one fragile spine posterodorsally. Gill rakers on the first arch are pointed and gradually become short towards the end. The body is covered with moderate-sized, overlapping ctenoid scales. The cheek scales cycloid, arranged in two rows.

There are two distinctly separate dorsal fins. The first dorsal fin is higher than the second, originating above the pectoral-fin base; its second spine is the longest, and the length of the succeeding spines decrease gradually. The base of the second dorsal fin is long, beginning at the midbody and not reaching the caudal-fin base when depressed. The anal fin originates slightly posterior to the anus, not reaching the caudal-fin base when depressed. The two disconnected pelvic fins are wide, roughly three-cornered, and shorter than the pectoral fin.

The body of Sillago muktijoddhai is greenish dorsally and light yellowish ventrally with black dots on the side below the lateral line. The cheek has black dots gathered on the anteroventral part of the eyes. The dorsal fins are hyaline, and small dark spots exist on the fin membrane, but those on the second dorsal fin form two or three distinct rows. The pectoral and pelvic fins are light yellowish. The anal fin is light yellowish with black spots. The caudal fin is light yellowish, dusky, and with a white edge; the lobes are truncated or emarginated.

Sillago muktijoddhai from the Bay of Bengal, Bangladesh. Saha et al. (2022).

The second new species is named Sillago mengjialensis, where 'mengjialensis' means 'from Mèngjiālā', where Mèngjiālā is the Chinese name for Bengal, in reference to the fact that the species was discovered as part of a collaborative project between scientists from China and Bangladesh.

The body of Sillago mengjialensis is elongated, somewhat conical anteriorly, and cylindric posteriorly. The back edge of the preopercle is slightly toothed. The opercle only has one weak spine posterodorsally. The gill rakers on the first arch are pointed and gradually become small towards the end. The body is covered with moderate-sized, overlapping ctenoid scales. The cheek scales are cycloid, arranged in two rows.

There are two disconnected dorsal fins. The first dorsal fin is higher than the second, originating above the pectoral fin base; its second spine is the longest, and the length of the succeeding spines decreases gradually. The base of the second dorsal fin is long, beginning at the midbody, and not reaching the caudal-fin base when depressed. The anal fin originates slightly posterior to the anus, not reaching the caudal-fin base when depressed. Two disconnected pelvic fins are large, roughly trigonal in shape, and smaller than the pectoral fin.

The body of Sillago mengjialensis is light olive greenish dorsally and silver ventrally with black spots on the sides below the lateral line. The cheek has black spots gathered on the anteroventral part of the eyes. The dorsal fins are hyaline with small dark spots on the fin membrane adjacent to the ray. The pectoral and pelvic fins are light yellowish. The anal fin is light yellowish to whitish with black dots. The caudal fin light yellowish, dusky, and has a white margin; the lobes are truncated or emarginated.

 

Sillago mengjialensis from the Bay of Bengal, Bangladesh. Saha et al. (2022).

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