Paracallisoma Chevreux 1903

Taxon classification Animalia Amphipoda Scopelocheiridae

Paracallisoma Chevreux, 1903

Paracallisoma Chevreux, 1903: 84. - Schellenberg 1926: 257. - Chevreux 1935: 39. - Gurjanova 1962: 308. - J.L. Barnard 1969: 305, key K. - Barnard and Karaman 1991: 454 (key), 510.

Scopelocheirus. - Barnard and Karaman 1991: 528 (in part).

Type species.

Paracallisoma alberti Chevreux, 1903, original designation.

Included species.

Paracallisoma includes seven species: Paracallisoma abyssi Oldevig, 1959; Paracallisoma alberti Chevreux, 1903; Paracallisoma coecum (Holmes, 1908); Paracallisoma platepistomum Andres, 1977; Paracallisoma spinipoda Hendrycks & Conlan, 2003; Paracallisoma woolgoolga sp. n.; Paracallisoma zivianii sp. n.

Diagnostic description.

Mandible lacinia mobilis a stemmed, distally expanded, smooth or minutely serrate blade. Maxilla 1 inner plate with pappose setae lining inner margin; palp 2-articulate. Maxilla 2 inner and outer plates subequal in width or inner plate slightly broader than outer plate, inner plate slightly shorter than or subequal in length to outer plate. Maxilliped palp article 4 well developed. Gnathopod 1 coxa large, margins subparallel or diverging distally; basis linear; dactylus small, simple, highly modified with apical tip. Pereopod 3 carpus short to long, longer than wide. Pereopod 4 coxa with strongly-developed, subacutely produced posteroventral lobe.

Discussion.

In addition to the two new species described herein, Horton et al. (2013) record an additional five undescribed species of Paracallisoma from the North Atlantic Ridge, and Duffy et al. (2012) record two undescribed species from submarine canyons of the Iberian Peninsula. These records indicate that there is still a large knowledge gap in the diversity of deep-sea scopelocheirids.