Oplophorus gracilirostris A. Milne-Edwards, 1881

Alves-Júnior, Flavio De Almeida, Silva, Elinai Dos Santos, Araújo, Marina De Sá Leitão Câmara De, Cardoso, Irene, Bertrand, Arnaud & Souza-Filho, Jesser F., 2019, Taxonomy of deep-sea shrimps of the Superfamily Oplophoroidea Dana 1852 (Decapoda: Caridea) from Southwestern Atlantic, Zootaxa 4613 (3), pp. 401-442 : 428

Oplophorus gracilirostris A. Milne-Edwards, 1881

( Fig. 31 A–B, 32 , 40 F)

Oplophorus longirostris Spence Bate, 1888: 765 , pl. 127, fig. 2.

Hoplophorus smithii Wood-Mason & Alcock, 1891: 194 .

Oplophorus gracilirostris A. Milne-Edwards, 1881: 6 .— de Man 1920: 48.— Chace 1947: 44, figs 4–7; 1986: 59, fig. 32a–e. — Vereshchaka 1990: 140.— Poupin 1998: 9.— Ramos-Porto et al. 2000: 77.— Cardoso & Young 2005: 52 , figs. 39–43.

Material examined. 1 F, Rio Grande do Norte, Potiguar Basin MT# 64-2 , Bottom trawl, m 416 m, 04° 36,24’ S / 036° 45,73’ W; 04° 36,52’ S / 036° 44,58’ W, 12 May 2011, MOUFPE : 15.673. 2 M and 1 F, Rocas Atoll, Abracos 1 ST# 14/ leg. 1, Midwater tow, 510 m, 03°58,97’ S / 034°03,37’ W, 0 6 October 2015, MOUFPE : 15.663. 1 F, Rocas Atoll, Abracos 1 ST# 22/ Leg. 1, Midwater tow, 57 m, 04°07,72’ S / 033°47,45’ W, 0 8 October 2015, MOUFPE : 15.595. 1 F, Rio Grande do Norte, Abracos 1 ST# 25/ Leg. 1, Midwater tow, 75 m 05°48,14’ S / 034°57,11’ W, 11 October 2015, MOUFPE : 15.576. 3 M and 2 F, Paraiba, Abracos 1 ST# 28/ Leg. 1, Midwater tow, 57 m 06° 37,30’ S / 034° 45,53’ W, 13 October 2015, MOUFPE : 15.668. 1 M, Pernambuco, Abracos 1 ST# 51/ Leg. 2, Midwater tow, 570 m, 08° 56,49’ S / 034° 29,05’ W, 19 October 2015, MOUFPE : 15.591.

Diagnosis: Carapace with rostrum overreaching scaphocerite, ventral margin with six teeth; antennal spine present; branchiostegal spine present, without distinct carina; with sharp tooth near posterior end of ventral margin; with posterior extensions of upper lateral rostral carina subparallel in dorsal aspect. Scaphocerite with 14 teeth on outer margin, without barb near apex of inner margin. Abdomen not dorsally carinate on somite 6; pleura of somite 1 with small tooth on ventral margin; somites 3–5 with posteromesial tooth, the one of somite 3 distinctly strong (modified by Cardoso & Young 2005).

Distribution: Western Atlantic: Gulf of Mexico, Bahamas, off Dominica, Lesser Antilles, Caribbean Sea, Brazil (Amapá, Pará, Ceará, Rio Grande do Norte, Rocas Atoll, Paraíba, Pernambuco and Bahia). Indo-Pacific Oceans: southeastern Africa, Indonesia, Philippines, southern Japan, Fiji Islands, Hawaii, French Polynesia, Seamounts Sala y Gòmez, Nazca ridge ( Chace 1986; Kensley 1987; Vereshchaka 1990; Cardoso & Young 2005) ( Fig. 32 ).

Bathymetric distribution: 100–2400 m depth ( Chace 1986; Vereshchaka 1990; Ramos-Porto et al. 2000), herein this species was collected between 57–570 m, thus extending its bathymetric distribution from shallow waters.

Remarks: The material examined agrees with the description and figures of Chace (1947; 1986) and Cardoso & Young (2005). Two species of Oplophorus are recorded from Brazilian waters: O. gracilirostris and O. spinosus ( Brullé, 1839) . These species differ from each other by (characters of O. spinosus in parentheses): carapace with a posteroventral tooth (vs without a posteroventral tooth), scaphocerite without a barb on the distal inner margin (vs with a barb on the distal inner margin) and first abdominal somite with a ventral tooth (vs somite without ventral tooth or with reduced ventral tooth) (Cardoso & Young 2005). This species occurs in mesopelagic zones from In- dian, Pacific and Atlantic oceans (Chace 1986; Kensley 1987). From Brazilian waters, the species O. gracilirostris was recorded by Ramos-Porto et al. (2000) and Cardoso & Young (2005). This paper reports O. gracilirostris for the first time in an oceanic island (Rocas Atoll).

Figures

FIGURE 31. Oplophorus gracilirostris A. Milne-Edwards, 1881. A. Female, lateral view. B. Telson, dorsal view (MOUFPE: 15.673). Scale bar = 0.5 cm.

FIGURE 32. Global geographic distribution of Oplophorus gracilirostris A. Milne-Edwards, 1881. Black circles = previous records; star = new record.

FIGURE 40. Deep-sea shrimps of the families Acanthephyridae Spence Bate, 1888 and Oplophoridae Dana, 1852 being: A. Ephyrina ombango Crosnier & Forest, 1973 (MOUFPE: 18.399). B. Meningodora compsa (Chace, 1940) (MOUFPE: 18.354). C. Notostomus elegans A. Milne-Edwards, 1881 (MOUFPE: 18.401). D. Notostomus gibbosus A. Milne-Edwards, 1881 (MOUFPE: 18.447). E. Janicella spinicauda (A. Milne-Edwards, 1883) (MOUFPE: 15.661). F. Oplophorus gracilirostris A. Milne-Edwards, 1881 (MOUFPE: 15.673), with material collected in Northwestern Brazil.