Rhabdosoma brevicaudatum Stebbing, 1888

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 : 226

Rhabdosoma brevicaudatum Stebbing, 1888

Rhabdosoma brevicaudatum Stebbing, 1888: 350 (key), 357; Brusca, 1981: 12 (list), 32 (key), fig. 21d; Siegel-Causey, 1982: 357; Vinogradov et al., 1996: 536 (key), 540‒541, fig. 233; García Madrigal, 2007: 157 (list); Gasca, 2009: 89 (tab. 1); Lavaniegos & Hereu, 2009: 152 (appendix); Lavaniegos, 2014: 5 (tab. 1); Valencia et al., 2013: 52 (tab. 1); Zeidler, 2016: 79 (passim), fig. 36D, 80 (key); Violante-Huerta et al., 2021: 81 (tab. 1), 84‒85, fig. 2C.

Material examined. 4F in one locality ( Fig. 3 ).

TALUD V. St. 5 (22°00’57”N, 106°40’00”W), December 13, 2000, 4F , MN from surface to ca. 1400 m (TD> 1600 m) (ICML-EMU-12964) .

Distribution. Subtropical Pacific Ocean, Atlantic Ocean from equator to 40°N; Mediterranean Sea. In the eastern Pacific from California to Costa Rica and Panama (García Madrigal 2007, Valencia et al. 2013, Violante-Huerta et al. 2021, this study).

Remarks. The specimens identified as R. brevicaudatum have a very small article on top of callynophore, smaller than in Zeidler’s (2016) key, the telson length is about 1/3 of the length of the double urosomite and does not reach the tip of uropod 2. The specimens examined are very similar to those of R. minor examined herein. Males of this species are not kown.

Reported as rare in the central and southern Gulf of California by Siegel-Causey (1982), a pattern confirmed during our study ( Fig. 3 ). Also present in the Mexican portion of the California Current ( Lavaniegos & Hereu 2009, Lavaniegos 2014).

Figures

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