Caridea

In the dark, expansive habitat of the deep sea, the production of light through bioluminescence is commonly used among a wide range of taxa. In decapod crustaceans, bioluminescence is only known in shrimps (Dendrobranchiata and Caridea) and may occur in different modes, including luminous secretions that are used to deter predators and/or from specialised light organs called photophores that function by providing camouflage against downwelling light. Photophores exhibit an extensive amount of morphological variation across decapod families: they may be internal (of hepatic origin) or embedded in surface tissues (dermal), and may possess an external lens, suggesting independent origins and multiple functions...

Bioluminescence is a prevalent phenomenon throughout the marine realm and is often the dominant source of light in mesophotic and aphotic depth horizons. Shrimp belonging to the superfamily Oplophoroidea are mesopelagic, perform diel vertical migration, and secrete a bright burst of bioluminescent mucous when threatened. Species in the family Oplophoridae also possess cuticular light-emitting photophores presumably for camouflage via counter-illumination. Many species within the superfamily express a single visual pigment in the retina, consistent with most other large-bodied mesopelagic crustaceans studied to date...

A new species of alvinocaridid shrimp is reported, from the Northwest Eifuku hydrothermal vent field at 16191667 m depth on the Mariana Arc. A comprehensive phylogenetic reconstruction of Alvinocarididae based on the mitochondrial cytochrome c oxidase subunit I (COI) gene including this new species reveals the paraphyly of the genus Rimicaris Williams & Rona, 1986 with four other generaAlvinocaridinides, Manuscaris, Opaepele, and Shinkaicarisnested within it. We re-examine material of these four problematic genera, and synonymise them under Rimicaris whose diagnosis has been amended, in order to maintain a monophyletic Rimicaris...

Macrobrachiumlanchesteri (De Man, 1911), a translucent freshwater prawn has a wide distribution range throughout mainland Southeast Asia. A high morphological variation and genetic divergence between different geographical M.lanchesteri populations in Thailand have peculiarly extended the uncertainty of species boundaries and blended confusingly with several Macrobrachium species. To clarify these circumstances, broad sample examinations of the morphological variation, including topotype specimens, and phylogenetic reconstruction based on the concatenated mitochondrial dataset (16s rRNA and COI genes) were performed...

Metacrimenes fenestra, a new palaemonid genus and species is described on the basis of an ovigerous female and one juvenile specimen from Suruga Bay, central Japan. The specimens were associated with the stalked crinoid Metacrinus rotundus Carpenter, 1885, collected at a depth of 131200 m. Photographs taken in situ indicate that the shrimp lives ectosymbiotically on its crinoid host. The greatly reduced bud-like exopod on the third maxilliped links the new genus to Mesopontonia Bruce, 1967 (Indo-West Pacific) and Waldola Holthuis, 1951 (East Pacific), in which the exopod is absent, but the presence of antennal spine on the carapace and the non-elongate, symmetrical second pereopods immediately distinguish Metacrimenes n...

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...

Species of the decapod family Palaemonidae are common components of tropical coastal waters and coral reefs. The majority of these species are symbionts of various invertebrate phyla. Despite a long history of research on their species diversity in the Dutch Caribbean, recent field expeditions have yielded much new information. Combined with examinations of specimens housed in Naturalis Biodiversity Center and information from literature, a comprehensive list of Dutch Carribean palaemonids is provided. Newly collected material was primarily identified via morphological analyses...

A new species of the thorid shrimp genus Heptacarpus Holmes, 1900, H. sadoi, is described and illustrated on the basis of six specimens from the southeastern coast of the Boso Peninsula, central Japan. All the specimens were collected from intertidal tide pools at low tide. Heptacarpus sadoi n. sp. belongs to the species group with epipods on the pereopods 13 and appears morphologically close to H. jordani (Rathbun, 1902) known from Japan and Korea. The new species is readily differentiated from H. jordani by the short rostrum with fewer dorsal teeth and the possession of only one spine on the distal margin of the basal article of the antennular peduncle...

Symbiotic species, living within or on the surface of host organisms, may evolve a wide range of adaptations as a result of various selection pressures, host specificity of the symbiont and the nature of the symbiosis. In tropical marine coral reef ecosystems, palaemonid shrimps (Crustacea: Decapoda: Caridea) live in association with at least five different invertebrate phyla. Host switches between (distantly) related host groups, and the thereby associated selection pressures were found to play a major role in the diversification of these shrimp lineages, giving rise to various host-specific adaptations...

The deep-sea environment is characterized by extreme and inhospitable conditions, including oxygen depletion, low temperatures, high pressure, absence of light, and limited food availability. Mitochondria and mitogenomes play a crudial role in aerobic respiration to generate energy for eukaryotes. Here, using the Illumina Hiseq 4000 platform, we performed mitogenome sequencing for five deep-sea caridean species: Lebbeus shinkaiae, Lebbeus Formosus, Glyphocrangon regalis, Heterocarpus dorsalis, and Heterocarpus laevigatus, and five deep-sea caridean mitogenomes were assembled and identified...

The early larval stages of the shrimps Lysmata ankeri and L. bahia were described, illustrated, and compared among other Lysmata species, providing important information on post-embryonic development and insights into its evolutionary history. Ovigerous specimens of L. ankeri and L. bahia were sampled from southeastern and northeastern Brazilian coast, respectively. For L. ankeri and L. bahia, five and three larval stages were obtained, respectively. Unique features were observed for L. ankeri and L. bahia larvae, and some characteristics may differ only for L...

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...

No abstract text is available yet for this article.

A new species of the alpheid shrimp genus Athanas Leach, 1814 is described based on a holotype from Wakasa Bay, Sea of Japan side of Honshu, Japan, at a depth of 90 m. Athanas exilis n. sp. appears close to A. sydnyensis Anker & Ahyong, 2007, but is distinguished from the latter by some morphological features, including the different shape of the telson, the shorter antennular stylocerite, more strongly produced distal lamella of the antennal scaphocerite, and less developed armature of the merus of the major cheliped...

To further understand the origin and evolution of Palaemonidae (Decapoda: Caridea), we determined the mitochondrial genome sequence of Palaemon macrodactylus and Palaemon tenuidactylus . The entire mitochondrial genome sequences of these two Palaemon species encompassed 37 typical genes, including 13 protein-coding genes (PCGs), 2 ribosomal RNA genes (rRNAs), and 22 transfer RNA genes (tRNAs), and a control region (CR). The lengths of their mitochondrial genomes were 15,744 bp ( P. macrodactylus ) and 15,735 bp ( P...

Lipids play essential roles in cell-structuring, cell-signaling, and as efficient metabolic energy stores. Lipid storage capacities determine life history traits of organisms and, thus, their ecological function. Among storage lipids, triacylglycerols (TAGs) are widespread in marine invertebrates. However, abilities to accumulate TAGs can vary even between closely related species, such as the caridean shrimps Crangon crangon and Pandalus montagui. The first species shows low TAG levels throughout the year in the main storage organ, the midgut gland, while the latter accumulates high TAG-levels, peaking in summer...

Knowledge on invasive species is critical for the conservation. This study is the first documentation on population parameters of oriental shrimp (Palaemon macrodactylus) in the southern Caspian Sea, where the occurrence of invasive species is of great importance. The samples were collected using a small beach seine (35 m long and 2.5 m height) monthly from April 2019 to March 2020, and a total of 1643 specimens of P. macrodactylus were sampled. The growth form of the males was negative and that of females positive allometric nature...

No abstract text is available yet for this article.

A new species of the freshwater shrimp of the genus Macrobrachium irwini sp. nov., is described from the Nandhini River near Kateel, Karnataka region of Western Ghats, India. 11 specimens of Macrobrachium irwini sp. nov. were collected from Nandhini river running through a secondary forest with heavily vegetated banks. The morphological analyses revealed that the new species can be clearly distinguished from the closely related species, M. snpurii and M. scabriculum based on the shape and dentition on rostrum, antennular peduncle, segmental ratios of first pereiopod, tubercles along the cutting edges of immovable and movable fingers of second major pereiopod and telson...

A new palaemonid species, Periclimenes variabilis, is described and illustrated on the basis of four specimens from the Ritto Seamount, West Marina Ridge, northwestern Pacific, at depths of 642-666 m. Specimens of the new species were collected with an unidentified hexacoral of Primnoidae (Cnidaria), an antipatharian octocoral Leiopathes sp. (Cnidaria), and an unidentified crinoid (Echinodermata), suggesting association with those invertebrates. Morphological comparison and molecular phylogenetic analyses using the mitochondrial 16S ribosomal RNA and cytochrome C oxidase subunit I genes indicate that the new species is closest to Periclimenes uniunguiculatus Bruce, 1990 although the possession of more than two spiniform setae on either side of the telson in the new species is consistent with the generic diagnosis of Bathymenes Kou, Li & Bruce, 2016...