How many valid Pleurosicya (Teleostei: Gobiidae) species are known from the Red Sea?

Four species of the gobiid genus Pleurosicya are reported from the Red Sea: P. bilobata, P. mossambica, P. plicata, and P. prognatha. Pleurosicya bilobata is reported as a new record for the Red Sea based on underwater photographs taken from a seagrass area at Dahab, Egypt, Gulf of Aqaba. A previous Red Sea record of P. micheli, a species occurring from Indonesia to French Polynesia, is based on a misidentification of P. mossambica and can be excluded as the Red Sea species. Phylogenetic COI barcode analysis showed that the genetic distance between Red Sea population and Western Indian Ocean specimens of P. mossambica is low, confirming the synonymy of P. sinaia, described from the Red Sea, with P. mossambica. Furthermore, phylogenetic analysis demonstrated that specimens from the western Pacific under the name P. mossambica are genetically distinct and may represent an undescribed species. Brief descriptions accompanied with underwater photographs are provided for four species of Pleurosicya from the Red Sea.

A new species of Fusigobius (Teleostei: Gobiidae) from the Red Sea and Gulf of Aden.

The gobiid species, Fusigobius humerosus sp. nov., is described based on 12 type and 18 non-type specimens collected from the Red Sea and Gulf of Aden. The new species can be distinguished from congeners by a combination of meristic and morphometric characters. The new species was formerly misidentified with F. humeralis: both are characterised by a semitranslucent body; head and body with numerous small dusky orange-yellow spots; a round black spot in humeral region just above base of pectoral fin; and a black spot subequal to pupil diameter at midbase of the caudal fin. However, Fusigobius humerosus sp. nov. differs from F. humeralis by scales on side of nape not extending forward to above posterior margin of preopercle (vs. scales variably extending forward to between above posterior preopercular margin and orbit); first dorsal-fin spine longest (vs. second and third dorsal-fin spines longest); shorter upper jaw; shorter anal-fin spine; and posterior nostril about halfway between orbit and anterior nostril (vs. posterior nostril closer to orbit). The most complete description of the genus Fusigobius is provided. In phylogenetic analyses of publicly available sequences of the barcoding portion of the mitochondrial cytochrome oxidase subunit I (COI) gene, sequences derived from the new species form a separate and well-divergent monophyletic lineage. The resulting COI gene tree further suggests that the new Fusigobius species is phylogenetically most closely related to F. humeralis which forms its sister species in the maximum likelihood tree. Molecular species delimitation of available Fusigobius COI barcodes shows that 19 or 20 hypothetical divergent evolutionary lineages can be deduced depending on the analytical approach (ABGD = 19 and bPTP = 20), indicating a potentially higher taxonomic richness than the presently acknowledged 11 valid species. However, the assignment of available species names for some lineages remains uncertain, highlighting the need for an additional integrative taxonomic research on this genus.

A new species of Trimma of the T. taylori species group (Teleostei: Gobiidae) from the Red Sea, Indian Ocean.

A new species of Trimma is described from the Red Sea along the Saudi Arabian coast. Specimens and/or photographs of this species are available from the Egyptian Red Sea to Eritrea. These specimens, formerly identified as T. taylori, differ from all other samples from the Indo-Pacific currently identified as T. taylori in having 9 and 89 dorsal- and anal-fin rays respectively (vs. usually 10 and 10 rays), 13 pectoral-fin rays (vs. usually 14 rays), and cycloid scales covering the entire predorsal region from the upper base of the pectoral fin anterior to a convex line posterodorsally to just lateral to the base of the sixth first dorsal-fin spine (vs. predorsal region mostly or entirely covered with ctenoid scales). In addition, specimens from the Red Sea form a monophyletic lineage in a Maximum Likelihood analysis of the COI gene. In this tree, the new species is the sister group to a clade composed of three lineages. One is composed of specimens from the Maldives, which is the sister group of a single available specimen from the Seychelles. These two together are the sister group of specimens of a widespread western Pacific clade.

Parrotfishes (Teleostei: Labridae: Scarini) of the Socotra Archipelago: Diversity and distributional biogeography, including a range extension of Scarus zufar Randall & Hoover, 1995.

An updated account of the diversity of parrotfishes from the Socotra Archipelago is provided. Fourteen species are positively recorded based on underwater observations, photography and collections, including confirmations of three species which were previously only tentatively recorded: Scarus falcipinnis(Playfair, 1868), Scarus scaber Valenciennes, 1840 and Scarus tricolorBleeker, 1847. The distribution of Scarus zufar Randall & Hoover, 1995, previously known only from coastal waters of southern Oman, Pakistan and Bangladesh, is extended to the Archipelago, with Abd al-Kuri Island representing the westernmost edge of its known range. Visual records of three additional species are yet to be documented. With 1417species the Archipelago approximates the modal richness range of 1518 species for Arabian ecoregions. A species account, accompanied by photographs, provides distinctive characters, distribution details in the Arabian region, and general remarks for each species. The distributional biogeography of the family pertinent to the Socotra Archipelago and the Arabian region is analysed in the context of the Western Indian Ocean. Three main Arabian units are identified: A Red Sea unit spans the combined Red Sea ecoregions and the western Gulf of Aden; a Socotra unit covers south-eastern Arabia including the Archipelago, the eastern Gulf of Aden and southern Oman; and a Gulf unit combines the Arabian/Persian Gulf, the Gulf of Oman, and putatively central Oman. These units form a discrete pan-Arabian cluster within the wider Western Indian Ocean. The Socotra unit resembles more strongly the Gulf unit than the Red Sea unit. Parrotfishes thus contrast overall distributional patterns of reef fishes in Arabia.

Identification of Mediterranean marine gobies (Actinopterygii: Gobiidae) of the continental shelf from photographs of in situ individuals.

Numerous photographs of live fishes posted by anglers and divers on social media and citizen science databases are important sources of information for ichthyological research. However, validating records that extend the known ecology and bathymetric or geographic distribution of species should rely on a rigorous identification process. The family Gobiidae, with their small size, superficial resemblance among species and high species richness are particularly difficult to identify. Therefore, the identification from photographs of live individuals of Mediterranean marine gobies from the continental shelf was studied. A dichotomous identification key is provided based on photographs of live individuals, allowing positive identification of 41 out of the 66 species reviewed in this publication. Then, for all 66 species we provide a brief description of important characters, which can be used for provisional identification for those species that could not be positively identified using the key. Pending further progress in identification of live individuals, we suggest that records extending the known geographic and ecological species distribution be taken into account only if they could be validated using the dichotomous identification key.

Biogeography of the coastal fishes of the Socotra Archipelago: Challenging current ecoregional concepts.

The Socotra Archipelago, located in the eastern Gulf of Aden, has a unique marine environment, which combines tropical and 'pseudo-temperate' elements. An updated species inventory recently considered its coastal fish diversity the highest among Arabian ecoregions, necessitating to re-assess the ichthyogeographic position of the island group. The main aim of this study is to describe the distributional biogeography of its coastal fish fauna in relation to contemporary ichthyogeographic and ecoregional concepts. Inferences are drawn with regard to the marine biogeographic arrangement and ecoregional partitioning of the Arabian region. The main datasets comprise eight and twenty selected families including 404 and 898 species, respectively, from Arabian ecoregions. The Socotra Archipelago has close affinities to a putative ecoregion in the eastern Gulf of Aden that extends to southern Oman. It is more closely related to the Arabian Sea coast of Oman than to ecoregions in the Red Sea and a putative ecoregion in the western Gulf of Aden. The Gulf of Aden does not represent a consistent ecoregion in ichthyogeographic terms, because its eastern and western parts are less closely related to one another than to other ecoregions. The Socotra Archipelago and the eastern Gulf of Aden should therefore not be assigned to a joined province with Red Sea ecoregions. The coastal fish faunas of the southern Red Sea have close affinities with those of the western Gulf of Aden. The Arabian/Persian Gulf is least related to the other Arabian ecoregions. The authors posit the Socotra Archipelago as a distinct ecoregion, either on its own or in combination with affiliated mainland areas. This best reflects the ichthyogeographic data and the exceptionally high levels of fish and overall marine diversity. Two alternative ecoregional delineations are proposed, serving as working hypotheses for onward research.

The taxonomic identity of the monocle bream Scolopsis vosmeri species complex (Perciformes: Nemipteridae), with comments on molecular phylogenetic relationships within the genus Scolopsis.

The monocle bream Scolopsis vosmeri species complex is revised. Three species in the complex are recognized: Scolopsis vosmeri (Bloch, 1792), widespread in the Indo-West Pacific, from the northern Indian Ocean (Pakistan, western India, Sri Lanka, Bay of Bengal, and the Andaman Sea, but not recorded from the Red Sea or Arabian Gulf, east African coast or Madagascar) to western Indonesia and Borneo; S. japonica (Bloch, 1793), restricted to the western Pacific Ocean from western Indonesia and north-western Australia east to the Philippines and north to southern Japan; and S. curite Cuvier, 1815, widespread from the western to the eastern Indian Ocean, including the Red Sea and Arabian Gulf. All three species are similar morphologically, and have been confused taxonomically, but phylogenetic analysis of the COI barcoding region shows they are evolutionarily divergent. The three species are redescribed in detail and characters found to distinguish them. Scolopsis vosmeri is easily distinguished from S. japonica and S. curite in having a white band along the side of the body; having a black spot on most body scales (versus greenish yellow spot in S. japonica and S. curite); in lacking a distinct black spot (sometimes a small and faint spot present) on the upper pectoral-fin base (versus small black wedge-shaped spot present in S. japonica and S. curite); caudal peduncle whitish in live individuals (versus caudal peduncle usually yellowish in S. japonica and S. curite); and pelvic and anal fins crimson to orange-red (versus yellow in S. japonica and S. curite). Scolopsis japonica and S. curite are indistinguishable by color pattern but differ in the degree of spination on the preopercular margin. Neotypes are designated for Scolopsis japonica and S. curite. Nomenclatural problems, including validity of the genus Scolopsis, are discussed. We regard Scolopsis curite Cuvier, 1815 as a valid binomial name and thus the type species of Scolopsis Cuvier, 1814 by subsequent monotypy.

Contributions to the taxonomy of the mugilid genus Chelon Artedi (Teleostei: Mugilidae), with a major review of the status of C. persicus Senou, Randall & Okiyama, 1995.

New data based on multigene phylogenetic analyses using the COI, 16S, and cytb genes and subsequent molecular species delimitation revealed that the mugilid genus Chelon contains 11 species. Of these, two species, Chelon sp. A and Chelon sp. B, remained unidentified in previous studies. While Chelon sp. B seemingly is a close relative to C. dumerili (Steindachner, 1870), no more detailed information were provided for Chelon sp. A which is present along the east coast of South Africa. Genetic analyses performed in this study, revealed that specimens from the Arabian/Persian Gulf and the Red Sea are nested within one genetic lineage alongside Chelon sp. A. Morphological, morphometric, and meristic analyses of specimens from all three areas demonstrated that they belong to Chelon persicus Senou, Randall & Okyiama, 1995. Chelon persicus was originally described in the genus Chelon but was later placed either in the genus Liza or Planiliza. However, results presented herein confirm its placement in Chelon and its distribution range is extended in the Western Indian Ocean from the type locality (Arabian/Persian Gulf) west to the Red Sea and south to South Africa. Further, the uncertain validity of the recently described Chelon caeruleus Deef, 2018 from the Mediterranean Sea and a previously proposed generic character distinguishing Chelon from Planiliza and Parachelon, the shape of the paired postzygapophyses of the second vertebra, are briefly discussed.

A new species of Hetereleotris (Teleostei: Gobiidae) from the Socotra Archipelago (north-western Indian Ocean), a rare case of a hole-associated adaptation in gobiid fishes.

A new cryptobenthic gobiid species Hetereleotris nasoramosa sp. nov. is described based on the holotype and five paratypes collected from the north-eastern part of Socotra Island, Arabian Sea, from moderately large pieces of coral rocks with holes at depths of 811 m. Molecular phylogenetic analysis placed the new species within the genus Hetereleotris. Hetereleotris nasoramosa sp. nov., differs from all species of Hetereleotris in having developed tentacles extending from each anterior and posterior nostril and five transverse suborbital papillae rows (instead four or six in other species). The new species superficially resembles the recently described Red Sea endemic species Cerogobius petrophilus by having forward-set, elevated eyes, a short snout, a moderately large mouth, a relatively deep and short caudal peduncle, and developed tentacles on the head, but differs from it by the same characters of developed tentacles extending from each anterior and posterior nostril and five transverse suborbital papillae rows as from other Hetereleotris species. Both species also share a specific habitat preference for tight holes in rock covered by micro-algae. A full description of the species is provided as well as a revised key to the species of Hetereleotris.

Review of the cardinalfishes of the genus Cercamia (Percomorpha: Apogonidae) of the Red Sea and Indian Ocean with descriptions of three new species.

The representatives of Cercamia from the Indian Ocean including Red Sea are reviewed and three new species are described: Cercamia spio n. sp., formerly known as C. eremia (Allen, 1987), is described from 14 specimens, 1733 mm SL, collected in 1015 meters from northern (Duba) to central (Jeddah) Saudi Arabia and from Jezirat Faraun, Egypt. It also has been photographed from the Gulf of Aqaba (Dahab, Egypt) and El Quseir (Mangrove Bay, Egypt). The new species is distinguished from other Indian Ocean Cercamia in having fewer developed gill rakers on lower limb (usually 11 versus usually 1213) and fewer anal-fin rays (11 versus usually 1213). Another new species, Cercamia laamu, n. sp., is described only from the Maldives and Chagos Archipelago based on five specimens 16.030.5 mm SL. It differs from all Indian Ocean Cercamia in having more greater number of the second dorsal-fin rays (10 versus usually 9), and a translucent body devoid of reddish marks versus small reddish dots and crisscross lines. The third new species, Cercamia mascarene, n. sp., is described from 40 specimens 1936 mm SL, from Rodrigues Island, Mauritius. It differs from Cercamia eremia in having a greater number of developed gill rakers on the lower limb of the first gill arch (usually 13 versus usually 12). Free neuromasts and cephalic pores are illustrated for Cercamia mascarene and free neuromasts on the body and caudal fin are illustrated for Japanese specimens of C. cf. eremia. New diagnoses are provided for Cercamia cladara, the type species of the genus, and C. eremia. A map of collection locations for species of Cercamia is presented to show the breath of known occurrences in the Red Sea and Indian Ocean. A new morphologic diagnosis is provided for Cercamia. A phylogenetic analysis of the barcoding portion of the mitochondrial COI gene, including all available sequences from members of the genus Cercamia, displays a much higher species diversity than expected, with high levels of divergence among recognized and undescribed species. A key to the described Indian Ocean species is provided.

Flying fishes (Beloniformes: Exocoetidae) of the Socotra Archipelago with comments on status of Exocoetus socotranus Steindachner.

A checklist of the flying fishes found in the waters off Socotra Archipelago, northwestern part of the Indian Ocean, is provided based on published and original data. Thirteen species from five genera occur in the study area, and four more species found nearby. Keys for the species identification are provided. The type specimen of Exocoetus socotranus Steindachner, 1902 was examined and is determined to be a junior synonym of Cypselurus naresii (Günther, 1889).

Notes on batoid fishes of the Socotra Archipelago (north-western Indian Ocean), with four new records.

The species composition of batoid fishes from coastal waters of the Socotra Archipelago is reviewed, with confirmed records of the wedgefish Rhynchobatus djiddensis (Forsskål, 1775) and four new records of sharkrays, wedgefishes, and guitarfishes based on collected specimens, including one species from Abd al-Kuri Island, Rhina ancylostoma Bloch Schneider, 1801 (Rhinidae), and three species from the main island Socotra, Acroteriobatus salalah (Randall Compagno, 1995) and Rhinobatos punctifer Compagno Randall, 1987 (Rhinobatidae), and Rhynchobatus australiae Whitley, 1939 (Rhinidae). Among the new records for the Socotra Archipelago, R. australiae represents the first verified record for the Arabian region. In addition, records of four stingray species (Dasyatidae) are verified based on underwater observations accompanied with photographs. All recorded batoid fishes are commercial species caught in the local small-scale fishery. Information on the identification and distribution of each species is provided.

Canthigaster aziz, a new deep-dwelling toby fish (Tetraodontiformes: Tetraodontidae) from the Red Sea.

A new species of toby fish, Canthigaster aziz, is described based on a single specimen collected from the northern Red Sea off Saudi Arabia. The holotype was trawled from a depth of 315 m, the second deepest record for the genus. The new species is distinguished from other species of the genus by the following combination of characters: 8 dorsal-fin rays; 8 anal-fin rays; 15 pectoral-fin rays; dorsal-fin origin opposite to anal-fin origin; five diffuse, saddle-like, black blotches along dark yellowish dorsal edge of body between nape and dorsal-fin origin; dorsal half of body light brown with concentrated dark pigments just behind eye and with a longitudinal, irregular, pale golden stripe running from area just behind eye to dorsal side of caudal peduncle; ventral half of posterior part of body pinkish with tiny subcutaneous black spots; head and ventral half of body before anus white; and all fins uniformly pale grey. A phylogenetic analysis of the mitochondrial COI barcoding region resulted in a new and unique evolutionary lineage for the new species that is sister to a clade composed of C. leoparda, C. pygmaea and C. valentini. It also shows C. aziz to be evolutionary deeply divergent from its closest congeners. In addition to the description of the new species, comparisons with congeners and a revised key to the Indo-Pacific species are provided.

Description of a new snake eel Ophichthus olivaceus (Teleostei: Anguilliformes, Ophichthidae) from the Red Sea.

A new species of snake eel Ophichthus olivaceus is described based on two specimens trawled from a depth of 35-63 m from a soft substratum off Jizan, Red Sea coast of southern Saudi Arabia. It differs from its congeners by the following combination of characters: vertebrae 141-145; tail moderately short (2.15 in TL); head short (9.6-11.1 in TL); uniserial teeth in jaws and on vomer; pectoral fins slightly elongate, not lanceolate, upper rays longer than the lower; dorsal-fin origin above middle of pectoral fin; and a generally uniform, dark tan body with an olivaceous hue shading to tan or pale orange ventrally, with two pale yellow blotches above pectoral-fin base, snout and lower jaw dark brown, and olivaceous median fins. Its divergence from other mitochondrial-analyzed species is shown by phylogenetic analysis of the mitochondrial COI barcoding region. A key to the Indian Ocean species is provided.

A new species of the cardinalfish genus Apogon (Teleostei, Apogonidae) from the southern Red Sea and Indian Ocean with comments on phylogenetic relationships within the Apogonini.

Apogon fugax is described as a new species of cardinalfishes based on a specimen trawled off Jizan (Saudi Arabia), southern Red Sea, at a depth of 60-67 m; two specimens trawled off southwest of Ayeyarwady Delta, Myanmar, at 54-129 m; and two specimens trawled off Western Australia at 166 m. The new species shares characters with the modified 'talboti look-alikes' species group (i.e., A. caudicinctus, A. dianthus and A. soloriens) as well as A. rubrifuscus and A. deetsie (both previously also assigned to the latter species group) in having two supraneurals, 12 pectoral-fin rays (13 rays in A. soloriens), and an enlarged, membranous, ventral preopercular edge. Molecular phylogenetic analysis of the apogonid tribe Apogonini, however, revealed that A. fugax n. sp. and its most closely related congeners, A. deetsie and A. rubrifuscus, form a separate phylogenetic clade unrelated to that formed by the 'talboti look-alikes' species group that is part of the A. unicolor species group. Apogon fugax n. sp. is distinguished from the species of the 'talboti look-alikes' species group, A. deetsie and A. rubrifuscus, in having a large head (2.2-2.4 in SL versus 2.4-2.8 in SL), longer first dorsal-fin spine (1.7-2.0 versus 2.7-4.0 in length of the second spine), and in their gill rakers count (developed gill rakers on the first gill arch 11-12 versus 8-9 in A. soloriens and 13-20 in the other four species).

Coastal fish diversity of the Socotra Archipelago, Yemen.

The Socotra Archipelago, located in the eastern Gulf of Aden, has a unique marine environment which combines tropical and 'pseudo-temperate' elements. Studies on the fish biogeography of the archipelago, partially framed in regional studies, have substantially outpaced critical elementary research on the archipelago's fish diversity. The present study seeks to close this gap and identifies the Socotra Archipelago as a major hotspot of coastal fish diversity in the Indian Ocean.       The archipelago supports unique coastal fish assemblages which are predominantly composed of coral-associated ("reef") species, in spite of the limited biogenic reef frameworks. A Preliminary Checklist comprises 682 species with confirmed records and a "Working List" includes an additional 51 records, totalling 733 faunal records in 108 families. The family Labridae is the most speciose, followed by Gobiidae, Pomacentridae, Serranidae and Chaetodontidae. The species richness of the archipelago is the highest when compared to adjacent Arabian ecoregions. The richness of the Acanthuridae, Chaetodontidae, Labridae, Pomacentridae and Pseudochromidae stand out as particularily high, and the richness of several families is as high as or higher than in the entire Red Sea. The total archipelagic richness is extrapolated at up to 875 species based on incidence-based richness models and expert opinion. Inshore fish inventories, covering 497 species, found between 14 and 132 species per site (x̄ = 66). Site diversity decreased across the archipelago from west to east and from north to south. Total fish diversity was highest around Socotra Island, followed by Abd al-Kuri Kal Farun and Darsa Samha. Occurrence frequencies were very unevenly distributed and dominated by Pomacentrus caeruleus and Thalassoma lunare, whilst many species were infrequent. The fish assemblages are dominated by species from the Indo-West Pacific and the north-western Indian Ocean. The assemblages are rich in rare species and hybrids, and include a low number of endemics (4-5), and a high number of species with far-reaching and Western Indian Ocean ranges.

Status of the cardinalfish genus Apogonoides and its type species Apogonoides macassariensis (Percomorpha: Apogonidae).

Apogonoides Bleeker 1849 is identified as the senior synonym of Cercamia Randall Smith 1988. We present evidence that Cercamia has become well established in the literature. Reversal of priority is proposed for the genus. The type species, macassariensis, is identified with Cercamia eremia (Allen 1987) based on geographic evidence. Reversal of priority is proposed for the species.

Description of a second species of Gymnoxenisthmus from the Red Sea (Teleostei: Gobioidei: Xenisthmidae).

Gymnoxenisthmus flavicinctus n. sp. is described from the 20.2 mm SL holotype collected from Sharm Obhur, Jeddah, Saudi Arabia, central Red Sea. It differs from the holotype and only known specimen of its congener G. tigrellus in having entirely unbranched pectoral-fin rays (versus only upper two rays and lowermost ray unbranched), 17 (versus 15) pectoral-fin rays and 13 (versus 12) segmented anal-fin rays. It also differs in live and preserved coloration. The new species brings the total number of xenisthmids known from the Red Sea to five.

Cerogobius petrophilus (Perciformes: Gobiidae), a new gobiid genus and species from the Red Sea.

A new genus and species of cryptobenthic goby, Cerogobius petrophilus is described from the Red Sea based on nine specimens not exceeding 2.5 cm in total length, collected from a stone-rubble habitat at Thuwal, Saudi Arabia, at depths of 8-15 m. It was also observed underwater at the southern tip of Ras Mohammed and Marsa Alam in Egypt. Cerogobius petrophilus sp. nov. is unique among other gobies in its habitat, and in this regard it superficially resembles some species of blennies, occupying tight holes in stones covered with short algae. Molecular phylogenetic data suggest a close relationship between Cerogobius petrophilus sp. nov. and Hetereleotris, but the former differs from the latter morphologically in head shape with specific proportions of orbit and snout, forward-set position of eyes, a moderately large mouth, a long horn-like tentacle at the nostrils in the middle of snout, caudal peduncle deep and short, and in details of cephalic sensory system. A full description of the new genus and species is provided and is accompanied with osteological data that potentially can be informative in further comparisons with Hetereleotris.

Two new species of Hetereleotris (Perciformes: Gobiidae) from the Red Sea.

Two new species of the gobiid genus Hetereleotris, H. aurantiaca sp. nov. and H. semisquamata sp. nov., are described from the Red Sea, the former from Saudi Arabia at Jeddah from the cave at depth of 14-16 m, and the latter from the southern Egypt from reef flat. Hetereleotris aurantiaca sp. nov. is distinguished from its congeners by having dorsal-fin rays VI + I,10; anal-fin rays I,9; pectoral-fin rays 14, all rays branched; pelvic-fin rays I,5, the fin separated and without frenum, 5th ray unbranched; anterior nostril with a long tube without process from the rim, posterior nostril a pore with erected rim; no tentacle above eye; posterior angle of jaws extending posteriorly to below posterior edge of pupil; no opercular spine; no mental frenum; pelvic fins longer than pectoral fins; squamation reduced to a few scales on caudal peduncle at caudal-fin base; no head canals; by presence, size and pattern of suborbital rows of sensory papillae; and orange head and yellowish orange body with five faint brown bars. Hetereleotris semisquamata sp. nov. is distinctive among its congeners by unique scale pattern (scales cycloid, the squamation reduced, tapering from caudal-fin base along lateral midline towards pectoral fin where nearly reaching its base) and by coloration (head and body whitish, with brown line from eye to end of upper lip, dark brown band across interorbital area and continuing obliquely from eye to corner of opercle, broad dark brown band below first dorsal fin continuing into fin, and moderately broad dark brown bar on caudal-fin base). Furthermore, it is characterized in having dorsal-fin rays VI + I,11, anal-fin rays I,10, pectoral-fin rays 16, and absence of head canals. In addition to descriptions of two species, a key to all species of Hetereleotris is provided. Hetereleotris psammophila is reported outside the Gulf of Aqaba for the first time.