Paronesimoides Pirlot, 1933

Tomikawa, Ko, Watanabe, Hiromi Kayama, Tanaka, Katsuhiko & Ohara, Yasuhiko, 2022, Discovery of a new species of Paronesimoides (Crustacea: Amphipoda: Tryphosidae) from a cold seep of Mariana Trench, Journal of Natural History 56 (5 - 8), pp. 463-474 : 465

Genus Paronesimoides Pirlot, 1933

Paronesimoides, 1933: 139; Barnard and Karaman 1991: 516; Larsen 2007: 2.

Diagnosis

Pleonite without dorsal carina. Urosomite 1 without dorsolateral flange. Antenna 1 slightly longer than antenna 2 or almost same length; male antennae with or without calceoli; female antennae lacking calceoli. Mandible incisor small; molar large, weakly triturative, not setose; palp attached opposite molar. Maxilla 1 inner plate with two apical setae; outer plate with 11 robust setae apically; palp two-articulate. Male gnathopod 1 larger than gnathopod 2, subchelate, posterodistal corner of palmar margin of propodus with two large, nodular robust setae. Female gnathopod 1 chelate. Uropod 2 inner ramus without notch. Uropod 3 short; inner ramus vestigial; outer ramus two-articulate. Telson short, entire.

Type species

Paronesimoides lignivorous Pirlot, 1933 , by monotypy.

Species composition

Paronesimoides contains three species: P. calceolus sp. nov., P. lignivorous, 1933 , and P. voightae Larsen, 2007 .

Remarks

Paronesimoides is most similar to Onesimoides Stebbing, 1888 in having well-developed maxilliped plates, subchelate male gnathopod 1, unnotched inner ramus of uropod 2, reduced inner ramus of uropod 3, and a short, entire telson. However, Paronesimoides is distinguished from Onesimoides by the longer peduncular article 2 of antenna 1 (0.5–0.6 times as long as article 1 in Paronesimoides vs 0.2–0.4 times in Onesimoides ) and the extremely reduced inner ramus of uropod 3 (less than 0.1 times as long as outer ramus of uropod 3 in Paronesimoides vs 0.5–1.0 times in Onesimoides ) ( Stebbing 1888; Pirlot 1933; Bellan-Santini 1974; Lowry and Stoddart 1993, 1994, 1996; Larsen 2007).