Description of a new species of the Alpheus edwardsii group (Decapoda: Alpheidae) with a distinctive colour pattern from the Indo-West Pacific.

A new snapping shrimp species of the Alpheus edwardsii (Audouin, 1826) group is described based on two specimens, one male and one female, collected on shallow-water reef flats of the Southern Ari Atoll in the Maldives, with a photographic record from Cebu in the Philippines. Alpheus octocellatus sp. nov. appears to be morphologically closest to A. edwardsii, A. pareuchirus Coutière, 1905, and A. leptochirus Coutière, 1905, but can be distinguished from all of them by a combination of morphological characters, mainly involving the chelipeds, third maxilliped and pleonal sternites. The new species also has a highly diagnostic colour pattern, with four pairs of conspicuous eyespots distributed in a unique and peculiar pattern on the pleon.

A conspicuously coloured new species of the Alpheus macrocheles group from the central Indian Ocean (Decapoda: Alpheidae).

A new snapping shrimp species of the Alpheus macrocheles (Hailstone, 1835) group is described based on a single adult male specimen collected on an exposed forereef near Magoodhoo Island, Faafu Atoll, Maldives. Alpheus dingabadi sp. nov. is one of several species of the A. macrocheles group characterised by the presence of a stout distoventral tooth on the merus of the third pereiopod, but can be separated from all of them by several morphological features, including the unusually long appendix masculina on the second pleopod, as well as by its conspicuous and highly diagnostic colour pattern.

Hidden in plain sight: two new species of decapod crustaceans (Palaemonidae and Porcellanidae) discovered in the Red Sea on a university campus in Saudi Arabia.

Two new symbiotic species of decapod crustaceans, a palaemonid shrimp and a porcellanid crab, are described from the same type locality situated on the campus of the King Abdullah University of Science and Technology (KAUST) in Thuwal, on the Red Sea coast of Saudi Arabia. The palaemonid shrimp Palaemonella jamila sp. nov. is described based on one male and one female, whereas the porcellanid crab Enosteoides habibi sp. nov. is described based on three males and two females. Unfortunately, the originally collected and studied specimens were lost shortly after study. However, subsequent recollection of one specimen of P. jamila sp. nov. and one specimen of E. habibi sp. nov. enabled to deposit a holotype of each new species in the collections of the Florida Museum of Natural History, Gainesville, USA. Both species inhabit burrows of goby-associated snapping shrimps, Alpheus spp., in the shallow subtidal areas, at depths less than 1 m. In addition, a single female specimen of Palaemonella aliska Marin, 2008 collected at Al Fahal reef off KAUST represents the first record of the species in the Red Sea and the Indian Ocean, and a considerable range extension of its previously known distribution range. This species may be a close relative of P. jamila sp. nov., to which it is also ecologically similar. The present study highlights the necessity of prospecting the largely neglected and still undersampled shallow subtidal habitats of the Red Sea, and the Indo-West Pacific in general.

A new deep-water species of Discias Rathbun, 1902 (Decapoda: Caridea: Disciadidae) from the Gulf of Aqaba, northern Red Sea.

A new species of the caridean shrimp genus Discias Rathbun, 1902 is described from the Gulf of Aqaba in the northern Red Sea off the coast of Saudi Arabia. Discias forsskali sp. nov. is unique within the genus Discias, combining the following morphological features: (1) rostrum elongate, triangular, pointed distally, non-lanceolate, with serrations on the lateral margins extending onto the orbital margin; (2) posterodorsal margins of all pleonites smooth, unarmed; (3) mandible with well-developed, biarticulated palp; (4) dactylus of third to fifth pereiopods with row of spinules on ventral margin, dactylus of fifth pereiopod smooth dorsally; (5) uropodal exopod with straight, non-serrated lateral margin; and (6) posterior margin of telson with nine (four pairs + one) spiniform setae. The holotype and single known specimen of the new species, an ovigerous female, was collected by ROV at a depth of 387.4 m.

Revision of Alpheus euphrosyne De Man, 1897 andA. microrhynchus De Man, 1897, with description of three new species and taxonomic remarks on several other morphologically and ecologically similar snapping shrimps (Malacostraca: Decapoda: Alpheidae).

Alpheus euphrosyne De Man, 1897 and A. microrhynchus De Man, 1897, two taxonomically challenging snapping shrimps without extant original type material, are rediagnosed based on recently collected and older museum material and adhering closely to their original descriptions. Two male specimens from Java and Kalimantan are designated as neotypes for A. euphrosyne and A. microrhynchus, respectively. Alpheus tirmiziae Kazmi, 1974 is placed in the synonymy of A. euphrosyne. The distributional range of A. euphrosyne extends from the South China Sea through the Sunda Shelf to the northern Arabian Sea. Alpheus eurydactylus De Man, 1920 is removed from the synonymy of A. euphrosyne and redescribed based on De Man's type material from Java and new material from South-East Asia, Indonesia and northern Australia. Alpheus richardsoni Yaldwyn, 1971, previously often regarded as a subspecies of A. euphrosyne, is confirmed as a valid species morphologically and ecologically distinct from A. euphrosyne. In addition, A. richardsoni is geographically separated from A. euphrosyne, being confined to subtropical and temperate waters of Australia and New Zealand. Alpheus microrhynchus appears to be geographically restricted to South-East Asia, with confirmed records from Thailand, peninsular Malaysia and Borneo, where it occurs in transitional freshwater to brackish water habitats. Alpheus cyanoteles Yeo & Ng, 1996 is currently seen as the only true freshwater snapping shrimp. This unique species is morphologically almost identical with A. microrhynchus and is presently known only from a few localities in southern Thailand, peninsular Malaysia and western Borneo (Sarawak). Three species that were previously confused with A. euphrosyne, A. euphrosyne euphrosyne or A. euphrosyne richardsoni, are described as new to science: A. nomurai sp. nov. from Japan, Korea and Taiwan; A. takla sp. nov. from South-East Asia, Philippines, Indonesia, Papua New Guinea and Australia; and A. mangalis sp. nov. from Singapore, Malaysia, Philippines, Indonesia, northern Australia, Taiwan and possibly New Caledonia. Alpheus takla sp. nov. may represent the largest presently known snapping shrimp, with the total body length reaching 90 mm and the length of the major chela reaching 52 mm; this species, locally known as takla, is consumed in some parts of the Philippines. The taxonomic identity of the material from the western and northern Indian Ocean previously reported as A. euphrosyne euphrosyne remains uncertain. Alpheus malabaricus songkla Banner & Banner, 1966 is tentatively elevated to species rank, as Alpheus songkla stat. nov. This taxon remains problematic, mainly because the original type material from Songkhla Lake, Thailand, is composed exclusively of females; its status is discussed based on the reexamination of type specimens and material tentatively identified as A. cf. songkla, which appears to have some affinities with both A. songkla and A. eurydactylus. In addition, taxonomic, biogeographic and/or ecological remarks are provided for five further species, which in the past were compared with A. euphrosyne, A. richardsoni and A. microrhynchus or are morphologically similar to them. These species are: A. paludicola Kemp, 1915 from India; A. nipa Banner & Banner, 1985 from Indonesia; A. bunburius Banner & Banner, 1982 from western Australia; A. pontederiae de Rochebrune, 1883 from both sides of the Atlantic Ocean; and A. firmus Kim & Abele, 1988 from the tropical eastern Pacific. The heterogeneity of the Panamanian and Mexican material currently assigned to A. firmus is discussed in more detail.

A distinctive new species of the coral shrimp genus Microprosthema Stimpson, 1860 from the Atlantic coast of Florida and Honduras (Decapoda: Stenopodidea: Spongicolidae).

A new species of the spongicolid coral shrimp genus Microprosthema Stimpson, 1860 is described on the basis of three specimens collected by hand while scuba diving off the Atlantic coast of southern Florida, with additional photographic records from Roatan, Honduras. Microprosthema dimitrisorum sp. nov. can be separated from all presently known species of the genus by a unique combination of morphological characters, and most easily, by its highly diagnostic and conspicuous colour pattern consisting of large red spots on most of the body and appendages.

Description of a new genus and new species of deep-water stenopodid shrimp from the western Atlantic, with remarks on Odontozona Holthuis, 1946 and Richardina A. Milne-Edwards, 1881 (Decapoda: Stenopodidea).

A new genus, Jogoya, gen. nov., is established for a new species of stenopodid shrimp, Jogoya alucia sp. nov., the holotype and single specimen of which was collected during a manned submersible dive in the Bahamas in 2019, and two additional specimens collected during earlier expeditions, one also from the Bahamas and one from Anguilla. The new genus appears to occupy an intermediate position between Richardina A. Milne-Edwards, 1881 and Odontozona Holthuis, 1946. Jogoya gen. nov. is characterised by the presence of unusually large spines on the cervical cincture of the carapace, a feature shared with a species originally described as Odontozona foresti Hendrickx, 2002 and herein tentatively transferred to Jogoya gen. nov., as Jogoya foresti (Hendrickx, 2002), comb. nov. The most conspicuous morphological difference between J. alucia sp. nov. and J. foresti is in the armature of the posterior half of the carapace, with the latter species having a post-cervical cincture armed with strong spines, which is absent in the new species. The two species of Jogoya gen. nov. also differ greatly by their colour patterns.

Revision of Salmoneus cristatus (Coutière, 1897) and Allied Forms (Decapoda: Caridea: Alpheidae).

Salmoneus cristatus (Coutière, 1897) is one of the first described species in the alpheid genus Jousseaumea Coutière, 1897, a name later invalidated and replaced by Salmoneus Holthuis, 1955. The species was described based on material from Djibouti and was initially characterised by the presence of a pronounced, posteriorly extending carina on the mid-dorsal line of the carapace, a shoulder-like elevation of the orbital hoods, and a red-banded colour pattern. Relying mainly on morphological features, various authors reported S. cristatus from several localities in the Indo-West Pacific, from the Red Sea to southern China and Australia. However, recently collected material attributable to S. cristatus on morphological grounds allowed for the combination of morphological characters, molecular data and colour patterns, demonstrating the existence of at least four species under the name of S. cristatus, including three species that are morphologically similar to, but phylogenetically distant from S. cristatus s. str. Therefore, S. cristatus is redescribed herein based on recent material from Saudi Arabia and Iran, as well as older material from Israel and Madagascar, with designation of a neotype from the Red Sea coast of Saudi Arabia. Three new species, viz. S. paracristatus sp. nov., S. franseni sp. nov., and S. alius sp. nov., are described based on recent material from Papua New Guinea for the former two species, and New Caledonia, Papua New Guinea and the Solomon Islands for the latter species. However, at least two of these new species seem to have wider distributions in the Indo-West Pacific.

A further new species of Palaemonella Dana, 1852 from the coasts of the Arabian Peninsula (Malacostraca: Decapoda: Palaemonidae).

Palaemonella yalla sp. nov. is described based on two ovigerous females: the holotype from Thuwal, Red Sea coast of Saudi Arabia, and a non-type specimen from Masirah Island, eastern Oman. The new species is very close to P. okunoi Komai & Yamada, 2015, from which it is essentially distinguishable by the distoventrally armed merus of the second pereiopods. The Saudi Arabian specimen was extracted from a burrow of an unknown host, whereas the Omani specimen was found in a muddy depression created after flipping a large rock deeply embedded in the sediment.

Alpheid shrimps of the genera Athanas Leach, 1814, Athanopsis Coutire, 1897 and Pseudathanas Bruce, 1983 of the coasts of the Arabian Peninsula (Malacostraca: Decapoda: Caridea).

Several species of alpheid shrimps belonging the genera Athanas Leach, 1814, Athanopsis Coutire, 1897 and Pseudathanas Bruce, 1983 (Decapoda: Caridea) are reported based on material collected on the Red Sea coast of Saudi Arabia and in Oman. Athanas claereboudti sp. nov. is described based on specimens from Masirah Island and Bandar Khayran east of Muscat, Oman, whereas A. iranicus Anker, Naderloo & Marin, 2010, A. minikoensis Coutire, 1903, A. parvus De Man, 1910, and a species tentatively identified as A. cf. dentirostris Anker, Jeng & Chan, 2001, are reported from various Omani localities. In the genus Athanopsis, four species are reported, including one species new to science: A. brevirostris Banner & Banner, 1981 from Saudi Arabia, A. dawa sp. nov. and A. rubricinctuta Berggren, 1991 from Masirah Island, Oman, and A. tarahomii Marin, Sheibani & Sari, 2014 from Saudi Arabia. The records of A. rubricinctuta and A. tarahomii represent second findings and significant extensions of their previously known ranges for these species. An important error in the description and illustration of the colour pattern of A. tarahomii is corrected, whereas the colour pattern of A. brevirostris is compared again with that of A. saurus Anker, 2011; the latter species is newly recorded from New Caledonia. The taxonomic identity of A. platyrhynchus Coutire, 1897, the type species of the genus from Djibouti, remains somewhat problematic. Finally, the monotypic genus Alberta Kazmi & Kazmi, 2010 established for Alberta banneri Kazmi & Kazmi, 2010 is placed in the synonymy of Pseudathanas Bruce, 1983 and Pseudathanas banneri (Kazmi & Kazmi, 2010) comb. nov. is reported from Muscat, Oman, for the first time since its original description. The generic diagnoses of Athanas, Athanopsis and Pseudathanas are emended to accommodate new or transferred species. All species reported are illustrated in colour.

Salmoneus shojaei, a new species of mangrove-dwelling alpheid shrimp (Decapoda: Caridea) from Iran.

During a survey of the mangrove infauna on the Iranian side of the Persian Gulf and the Gulf of Oman several specimens of a new alpheid shrimp, Salmoneus shojaei sp. nov., were collected around pneumatophores of mangrove trees, mostly in association with the larger burrowing snapping shrimps of the genus Alpheus Fabricius, 1798. The new species appears to be a member of the S. gracilipes species group and is morphologically closest to S. colinorum De Grave, 2004 and S. alpheophilus Anker Marin, 2006. However, a unique combination of morphological characters, such as the carapace without rostral carina, the unarmed ischium of the major cheliped, the armed ischia of the minor cheliped and second pereiopod, the very slender dactyli of the fourth and third pereiopods, and the posterior margin of the telson with a deep U-shaped notch, distinguishes the new species from all other members of the S. gracilipes group. In addition, S. shojaei sp. nov. presents a diagnostic, albeit very faint, banding of the pleon, which separates it from most other species of the S. gracilipes group with known colour patterns. A DNA barcode (a partial fragment of the mitochondrial gene, CO1), as well as partial fragments of the mitochondrial 16S rRNA and the nuclear H3 genes, are provided to genetically characterise the new taxon.

Three new species of the shrimp genus Salmoneus Holthuis, 1955 from the Red Sea, with a new record of S. poupini Anker, 2010 (Malacostraca: Decapoda: Alpheidae).

Three new species of the alpheid shrimp genus Salmoneus Holthuis, 1955 are described from the Red Sea coast of Saudi Arabia: S. farasan sp. nov. from the Farasan Islands; S. arabicus sp. nov. from Thuwal and Farasan Banks; and S. kausti sp. nov. from Thuwal. Salmoneus poupini Anker, 2011, previously known from French Polynesia and the Philippines, is reported for the first time from the Red Sea, based on material from Thuwal, Farasan Banks and Farasan Islands. In addition, the previously known distributional range of the closely related S. komaii Anker, 2011 is extended from the Mariana Islands to French Polynesia.

The first complete specimen of the deep-water shrimp Batella praecipua De Grave, 2004 (Crustacea: Decapoda: Alpheidae).

The deep-water alpheid shrimp Batella praecipua De Grave, 2004 was originally described based on two incomplete specimens, both with their first chelipeds missing, collected at 400440 m off New Caledonia. During the recent KANADEEP 1 expedition in the Coral Sea in 2017, the first complete specimen of B. praecipua was collected at a depth of 370380 m. The morphology of this specimen is presented in detail, with emphasis on the highly diagnostic chelipeds, which are described and illustrated for the first time. A slight intraspecific variation of B. praecipua is reported and a DNA barcode (CO1) is provided for this species. The main differences between the three presently known species of Batella Holthuis, 1955 are discussed.

Description of two new species of goby-associated snapping shrimps from the tropical western Pacific (Decapoda: Alpheidae: Alpheus).

Two new snapping shrimps associated with gobies are described from the tropical waters of the western Pacific. Alpheus thompsoni sp. nov. is described based on a single adult female from Madang, Papua New Guinea. Alpheus sciolii sp. nov. is described based on several specimens of both sexes from the Solomon Islands, Australia and Vietnam. Both species are part of a larger species complex, which also includes A. djeddensis Coutire, 1897, A. djiboutensis De Man, 1909, A. bellulus Miya Miyake, 1969, A. macellarius Chace, 1988, A. fenneri Bruce, 1994 and A. mannarensis Purushothaman, Abhilash, Kumar Lal, 2021, but can be distinguished from each of them by a combination of morphological characters, and from the latter four species also by the very different colour patterns.

First Atlantic record of the rare infaunal shrimp Salmoneus erasimorum Dworschak, Abed-Navandi amp; Anker, 2000 (Malacostraca: Decapoda: Alpheidae).

The rare symbiotic alpheid shrimp Salmoneus erasimorum Dworschak, Abed-Navandi Anker, 2000 was previously known from a single specimen collected with a suction pump on the Croatian coast in the Adriatic Sea, together with its host, the ghost shrimp, Gilvossius tyrrhenus (Petagna, 1792). A second record of S. erasimorum is presented here, with a diagnosis and the first colour photographs, based on a single specimen collected in northern Brittany, France, also with a suction pump, but without its host. This is also the first record of the species on the European coast of the Atlantic Ocean. An annotated list and a key to the species of Salmoneus currently known from the eastern Atlantic and the Mediterranean Sea are provided.

On two goby-associated snapping shrimps from the Red Sea, one of them new to science (Malacostraca: Decapoda: Alpheidae: Alpheus).

Two snapping shrimps associated with gobies are reported from the Saudi Arabian coast of the Red Sea. Alpheus karplusi sp. nov., a species with a highly diagnostic, rusty-spotted colour pattern, is described based on three specimens, two males and one female, collected in the Farasan Islands and off Thuwal. Alpheus thompsoni Anker, 2022, previously known with certainty only from Papua New Guinea, is reported from the Farasan Islands, on the basis of a complete adult male specimen. Some differences in the colour pattern and morphology between the female holotype from Papua New Guinea and the male from the Red Sea are discussed. Both species belong to the A. djeddensis Coutire, 1897A. djiboutensis De Man, 1909 species complex, which also includes A. bellulus Miya Miyake, 1969, A. macellarius Chace, 1988, A. fenneri Bruce, 1994, A. mannarensis Purushothaman, Abhilash, Kumar Lal, 2021, and A. sciolii Anker, 2022.

Crosnierocaris athanasoides gen. et sp. nov., a new deep-water alpheid shrimp from the Mozambique Channel (Malacostraca: Decapoda: Caridea).

A new alpheid shrimp genus, Crosnierocaris gen. nov., is established for Crosnierocaris athanasoides sp. nov., a very peculiar shrimp possibly associated with decomposing sea grass accumulations in deeper water. The type series of C. athanasoides sp. nov. was collected in the Mozambique Channel, north of Grande Glorieuse Island, at a depth of 240255 m. The new genus presents a unique combination of morphological features, including the very long, slender rostrum armed with a subdistal ventral tooth; the pterygostomial angle projecting as a strong sharp tooth; the third to fifth pleura with their distoventral margins armed with two to four small teeth, a unique feature within the Alpheidae; the sixth pleuron with an articulated plate; the eyes largely exposed dorsally and laterally; the first pereiopods (chelipeds) feebly enlarged in both sexes, stouter but shorter than walking legs; the first pereiopod carpus with rows of short serrulate setae on its mesial surface; the second pereiopod carpus with five subdivisions; the third to fifth pereiopods with meri armed with stout cuspidate setae; the uropodal diaeresis with a strongly dentate lateral portion; and the complete gill-exopod formula, with mastigobranchs on coxae of the third maxilliped and first to fourth pereiopods. Within alpheid shrimps, the rostrum of C. athanasoides sp. nov. is one of the longest relative to the total body length, often reaching half of the carapace length. The phylogenetic position of Crosnierocaris gen. nov. within the Alpheidae remains to be determined, but based on its morphological characters, the new genus appears to be closest to Athanas Leach, 1814, especially in the configuration of the frontal area of the carapace, and Potamalpheops Powell, 1979, for instance, in the armature of the uropodal diaeresis and walking legs, as well as the presence of setal rows on the cheliped carpus. The new genus also shares several morphological features with Yagerocaris Kensley, 1988, which represents one of the least derived lineages within the family Alpheidae.

Athanas philippei n. sp., a new alpheid shrimp associated with stomatopods in New Caledonia (Decapoda: Caridea).

A new stomatopod-associated species of the alpheid shrimp genus Athanas Leach, 1814 is described based on several specimens collected in shallow waters of northern New Caledonia. Athanas philippei n. sp. differs from all of its congeners by a unique combination of morphological characteristics, as well as a diagnostic colour pattern. All specimens of A. philippei n. sp. were collected from burrows, including one with its host, a large tiger mantis shrimp, Lysiosquillina maculata (Fabricius, 1793) (Lysiosquillidae). Thus, the new species represents the fifth species of Athanas known or presumed to be associated with the spacious burrows of stomatopods.

A new species and two new records of symbiotic infaunal alpheid shrimps from the genera Leptalpheus Williams, 1965 and Fenneralpheus Felder amp; Manning, 1986 (Decapoda: Caridea) from Venezuela.

Leptalpheus lirai sp. nov., a new species of symbiotically living, infaunal alpheid shrimp, is described based on a single specimen from the Gulf of Santa Fe, Sucre, Venezuela. The new species belongs to an informal group of nine species within the genus Leptalpheus Williams, 1965, which is characterised by the presence of well-developed adhesive disks on the major chela. In addition, Leptalpheus axianassae Dworschak Coelho, 1999 and Fenneralpheus chacei Felder Manning, 1986 are recorded for the first time from Venezuela (Anzotegui and Sucre, respectively), the latter also representing the first record of the genus Fenneralpheus Felder Manning, 1986 for the country. These records bring to 11 the number of alpheid genera, and to four the number of species of Leptalpheus, known in Venezuelan marine waters.