Rhabdosoma armatum (H. Milne Edwards, 1840)

Gasca, Rebeca & Hendrickx, Michel E., 2022, Pelagic amphipods (Crustacea: Amphipoda: Hyperiidea) in western Mexico. 7 Superfamily Platysceloidea. Family Oxycephalidae, Zootaxa 5105 (2), pp. 219-236 : 225-226

Rhabdosoma armatum (H. Milne Edwards, 1840)

Oxycephalus armatus H. Milne Edwards, 1840: 101 .

Rhabdosoma armatum .— Brusca, 1981: 12 (list), 32 (key), fig. 21b; Siegel-Causey, 1982: 350 (key), 351; Vinogradov et al., 1996: 536 (key), 536‒540, fig. 231; García Madrigal, 2007: 157 (list); Gasca, 2009: 89 (tab. 1); Lavaniegos & Hereu, 2009: 152 (appendix); Zeidler, 2016: 76‒79 (passim), figs. 35, 36A, 36Md, 36Mxp, 79 (key).

Material examined. 2F in two localities ( Fig. 3 ).

TALUD I. St. 5 (ca. 23°16’ N, 107°31’W), December 11, 1989, 1F, BO from surface to ca. 200 m (TD> 1500 m) (ICML-EMU-12962); St. 6 (23°15’54”N, 107°31’12”W), December 12, 1989, 1F, BO, from surface to 1550 m (TD> 2000 m) (ICML-EMU-12963) .

Distribution. Tropical and subtropical waters in the Pacific, Atlantic, and Indian Oceans. In the eastern Pacific from California to Peru ( Vinogradov et al. 1996, García Madrigal 2007, this study).

Remarks. Species of Rhabdosoma have an easily recognized slender and elongated body. Rhabdosoma armatum can be distinguished mainly by the shape and proportions of the telson, with double urosomite, and uropods.

Most commonly found in 25‒50 m depth ( Vinogradov et al. 1996). Rare in the southern Gulf of California and always present in surface waters ( Siegel-Causey 1982). Also recorded in the Mexican portion of the California Current ( Lavaniegos & Hereu 2009). Another rare species (two specimens in two localities) in our survey ( Fig. 3 ).

Figures

FIGURE 3. Localities where Rhabdosoma armatum, R. brevicaudatum, and R. minor were collected during this survey.