Paralomis spinosissima Birstein & Vinogradov 1972

• Main Authors: Olguín, Nicole, Ocampo, Emiliano H., Farias, Nahuel
• Format: Text
• Language: unknown
• Published: Zenodo 2015
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Malacostraca; Decapoda; Lithodidae; Paralomis; Paralomis spinosissima; Antarctic; The Antarctic; Scotia Sea; Pacific; Argentina; South Georgia Island; Macpherson; Guzmán; Ocampo; Antarc*
• Online Access: https://dx.doi.org/10.5281/zenodo.6093932; https://zenodo.org/record/6093932

Paralomis spinosissima Birstein & Vinogradov, 1972 (Figs. 1–2) Material examined. Mar del Plata, Argentina, station L 42 of the Talud II campaign, 37 ° 59.11 ’S, 54 ° 41.136 ’W, Slope II, 877 m, (25.V. 2013), R/V Puerto Deseado , 1 male (juvenile) cl = 13.61 mm, cw = 12.63 mm, MACN-In 39716. Diagnosis. Carapace subpentagonal or pyriform, slightly longer than wider, covered with long conical spines (Fig. 1). Juveniles have mushroom shape tubercles, with spiniform setae surrounding at the apex. Gastric region with a prominent spine. Branchial regions with acute spines. Lateral and posterior surface with small spines. Rostrum acute trispinose, overreaching the ocular peduncle; paired dorsal spines divergent, directed obliquely upwards, slightly shorter than the central, with a small spine between them (Fig. 2 A). Ocular peduncle with a longest dorsal spine overreaching the cornea; with scattered smaller spines along its length; some spines with several apical setae (Fig. 2 A, B). Scaphocerite slender, armed with a long central acute spine, two lateral smaller spines and one short inner spine (Fig. 2 B). Chelipeds and walking legs densely covered with long and acute spines; dorsal margin with prominent spines; ventral margin armed with blunt spines, in juveniles specimens have blunt tubercles with a tuft of long and rigid setae (Fig. 2 C, D, E). Distribution. Southeast Atlantic, Scotia Sea, South Georgia Island (Birstein & Vinogradov 1972), and between the Burwood Bank and the Malvinas Islands (Macpherson 1988 a), and now from Mar del Plata. Depth range: 132 and 877 m. Remarks. The specimen examined agrees with the description by Birstein & Vinogradov (1972) except for the armature of the scaphocerite, which has two pairs of lateral spines, and in the specimen analyzed here, just one spine on the inner side. However, Macpherson (1988 b) noted that in the holotype, the inner side of the scaphocerite has three spines; this character may be variable in juvenile and adult specimens. The variations of this new specimen could be related to its juvenile stage. The species is distinguished from all other described species of Paralomis by the armature of the carapace, chelipeds and walking legs that are densely covered by acute spines. Eleven species share this character (Guzmán 2009), but only P. erinacea Macpherson, 1988, P. sonne Guzmán, 2009 closely resemble P. spinosissima because they are more densely covered with spines than, for instance, P. f or m os a Henderson, 1888 and P. spectabilis Hansen, 1908. Moreover, these spines are not as long as in P. phryxa Macpherson, 1992, P. hystrix (de Haan, 1844) and P. hystrixoides Sakai, 1980. The differences between P. erinacea and P. spinosissima were discussed by Macpherson (1988 b) and are based mainly on the presence of thick spines in the gastric and branchial regions in the latter species. Our specimen is agree with the Macpherson’s observations in the presence of thick spines in the gastric and branchial regions. On the other hand, the rostrum of P. spinosissima differs from P. sonne in the shape and number of the spines; P. sonne bears two pairs of lateral spines and just one in P. spinosissima . Other differences are in the armature of the pereiopods, more densely covered in P. spinosissima than P. sonne (Guzmán 2009). The present specimen from Mar del Plata extends significantly the distribution of the species northwards. : Published as part of Olguín, Nicole, Ocampo, Emiliano H. & Farias, Nahuel, 2015, New record of Paralomis spinosissima Birstein & Vinogradov (Decapoda: Anomura: Lithodidae) from Mar del Plata, Argentina, pp. 239-242 in Zootaxa 3957 (2) on pages 240-241, DOI: 10.11646/zootaxa.3957.2.9, http://zenodo.org/record/232856 : {"references": ["Birstein, J. A. & Vinogradov, L. G. (1972) Craboids (Decapoda, Anomura, Lithodidae) of the Atlantic sector of the Antarctic, South America and South Africa (in Russian). Zoologicheskii Zhurnal, 51, 351 - 363.", "Macpherson, E. (1988 a) Three new species of Paralomis from the Pacific and Antarctic Oceans. Zoologica Scripta, 17, 69 - 75. http: // dx. doi. org / 10.1111 / j. 1463 - 6409.1988. tb 00087. x", "Macpherson, E. (1988 b) Revision of the Family Lithodidae Samouelle, 1819 (Crustacea: Decapoda: Anomura) in the Atlantic Ocean. Monografias de Zoologia Marina, 2, 1 - 153.", "Guzman, G. (2009) Paralomis sonne nueva especie de Litodido (Decapoda, Paguroidea, Lithodidae) en aguas profundas frente a Antofagasta, Chile. Latin American Journal Aquatic Research, 37, 1 - 5. http: // dx. doi. org / 10.3856 / vol 37 - issue 2 - fulltext- 12"]}