Gennadas talismani Bouvier, 1906

Alves-Júnior, Flavio De Almeida, Lemos, Rachel De Jesus Feio De, Cardoso, Irene Azevedo, Araújo, Marina De Sá Leitão Câmara De, Bertrand, Arnaud & Souza-Filho, Jesser F., 2018, New records of deep-sea prawn of the genus Gennadas Spence Bate, 1881 (Crustacea: Decapoda: Benthesicymidae) from Southwestern Atlantic, Zootaxa 4450 (3), pp. 376-384 : 382

Gennadas talismani Bouvier, 1906

( Figure 5 A‒B )

Gennadas talismani Bouvier, 1906: 749 .— Lenz & Strunk 1914: 311 –313, plate XVIII fig. 1–14.— Crosnier & Forest 1969: 549.— Kensley 1971: 289, 290, fig. 11; 1972, fig. 4j, 6d.

Material examined. 1 Male (CL, 6.79 mm), Mid-Atlantic Ridge, project-Mar Eco 34829, Superstation 3, serial 1013, 04°16’42’’S, 12°22’39’’W, 3093 m, MNRJ 22573 . ST47, 1 Male (CL, 3.3 mm), Fernando de Noronha Archipelago , 4°25'5''S, 32°57'51''W, 505 m, 30 April 2017, MOUFPE 18743 . ST56C, Seamounts- Ceará Chain, 2 Males (CL, 3.2 mm, 3.3 mm), 3°58'46''S, 35°23'2''W, 260 m, 0 4 May 2017, MOUFPE 18698 .

Diagnosis. Carapace thin. Antennal and infra-antennal angles acute. Thelycum with shield on 8th sternite notched anteriorly and posteriorly, 7th sternite with broad rectangular plate, anterior ridge marking position of seminal receptacles. Petasma with internal lobe rounded, external lobe forming 2 low apically acute lobules, small hooks in posterior region; median lobe bipartite, outer lobule broad, inner lobule slender. Interior lobe rounded and accessory lobe a broad flap.

Distribution. Western Atlantic: Gulf of Mexico, Brazil (Seamounts of Ceará Chain and Fernando de Noronha Archipelago) ( Figure 2 ). Eastern Atlantic: Mid-Atlantic Ridge (Walvis Ridge), Cape Verde, Gabon, Angola, South Africa ( Crosnier & Forest 1969; Kenley 1971; Kensley et al. 1987).

Bathymetric Distribution. 100‒4000 m depth ( Kensley 1971; Kensley et al. 1987).

Remarks. Crosnier & Forest (1969) observed a small branchiostegal spine followed by a carina running toward posterior margin of carapace, lacking in our specimens, this characteristics may be presented as a little variation between specimens collected in South Atlantic waters. According to Kensley (1971), the species closest to G. talismani is G. valens ( Smith, 1884) . They can be distinguished as follows: 7th sternite of thelycum of G. talismani with broad, rectangular plate, anterior ridge marking position of seminal receptacles while in G. valens this structure is sternite of thelycum of G. talismani present the inter lobe of the median lobule slender, while in G. valens the inter lobe is robust. Gennadas talismani is endemic to the Atlantic Ocean ( Kensley et al. 1987), but it is recorded for the first time in the southwestern Atlantic.

Figures

FIGURE 2. Sampling stations visited during this study where specimens of Gennadas were collected (Abracos 2 and MAR- ECO Projects).

FIGURE 5. Gennadas talismani Bouvier, 1906, Male (CL, 3.3 mm), Petasma (C) (IL= Internal Lobe; AL= Accessory Lobe; ML: Median Lobe; EL= External Lobe), Abracos 2 ST# 47, 505 m, MOUFPE 18743.