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| Allorchestoides rosea
Wongkamhaeng, Dumrongrojwattana & Shin, 2018
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Abstract
During a scientific survey, a new genus of the dogielinotid amphipoda was found in the Nipa palm (Nypa fruticans) in Bang Krachao Urban Oasis, Samut Prakan Province, Thailand. We placed this new genus, Allorchestoides gen. nov., within the family Dogielinotidae. The new taxa can be easily distinguished from the remaining genera by differences in the incisor of the left and right mandibles, apical robust setae of the maxilla 1, and the large coxa and strong obtuse palm in the female gnathopod 1. The type species of Allorchestoides gen. nov., Allorchestoides rosea n. sp., is described here in, with an updated key to the genera of the family Dogielinotidae.
Order Amphipoda Latreille, 1816
Suborder Senticaudata Lowry & Myers, 2013
Family Dogielinotidae Gurjanova, 1953
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| Fig 2. Allorchestoides rosea sp. n., holotype, male, (PSUZC-CR-00300). |
Allorchestoides gen. n.
Diagnosis: Male. Mouthparts, mandible, right incisor process four dentate; left incisor process six dentate; accessory setal row present; molar triturative. Maxilla 1 outer plate with six distal setal-teeth. Maxilla 2, inner plate with an enlarged proximal seta; outer plate subequal to inner plate in length. Maxilliped, outer plate shorter than article 2 of maxilliped palp; palp well-developed, dactyl unguiform. Coxal plates 1–4 deep, subrectangular; coxal plate 1–3 posterior marginal cusp absent. Gnathopods sexually dimorphic. Male gnathopod 1 weakly chelate; carpal lobe well-developed; palm slightly protruding at palmar corner, dactylus fitting palm. Gnathopod 2 propodal palm smoothly concave, interior margin lined with pappose setae. Epimeral side plates ordinary, plate 2 deepest. Pleopods peduncle with 2 small retinacula;
Female. Gnathopods 1 and 2 weakly chelate; carpal lobe well-developed, surpassing over propodus.
Type species: Allorchestoides rosea, new species, here designated.
Etymology: The specific name, Allorchestoides, alludes to fact that the new genus is allied to Allorchestes Dana, 1849. The gender is feminine as the gender adopted by its original authors.
Remarks: The new genus is similar to Allorchestes Dana, 1849, from the north and south Pacific, because it has a dactylus of maxilliped unguiform; carpus of male gnathopod 2 lobate, projecting between the merus and propodus; uropod 3 uniramus; and telson cleft that is half-length. However, the 1-articulate maxilla 1 palp in Allorchestes is reduced and tiny, not reaching the base of the setal-teeth of the outer lobe, while that of Allorchestoides gen. n. is absent.
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| Fig 3. Allorchestoides rosea sp. n. holotype male (PSUZC-CR-00300). (A) male body, lateral (PSUZC-CR-00300), (B) antenna 1, (C) antenna 2, (D) gnathopod 1, (E) gnathopod 2.
Scales bars: 0.5 mm.
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| Fig 7. Allorchestoides rosea sp. n. Allotypes, female, (PSUZC-CR-00301). (A) Female body, lateral, (B) antenna 1, (C) antenna 2, (D) gnathopod 1, (E) gnathopod 2.
Scales bars: 0.5 mm.
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Allorchestoides rosea n. sp.
Etymology: This species is named after the distinct reddish color while the amphipod alive (Fig 2).
Type locality: THAILAND, Bang Krachao Estuary near Chao Phraya River mouth (13°41'47.4"N 100°33'52.4"E), Nipa Palm leafs in mangrove forest, 2016, Dumrongrojwattana,P.
Type material: Holotype. ♂, PSUZC-CR-0300. Allotype, ♀ collected with holotype;..
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| Fig 1. Map of sampling area; THAILAND, Bang Krachao Estuary near Chao Phraya River mouth. |
Koraon Wongkamhaeng , Pongrat Dumrongrojwattana, Myung‐Hwa Shin. 2018. Discovery of A New Genus and Species of Dogielinotid Amphipod (Crustacea: Amphipoda: Dogielinotidae) from the Nipa Palm in Thailand, with An Updated Key to the Genera. PLoS ONE. 13(10); e0204299. DOI: 10.1371/journal.pone.0204299
