Plesiopenaeus armatus ( Bate, 1881 )

Tavares, Carolina R. & Serejo, Cristiana S., 2007, Taxonomy of Aristeidae (Dendrobranchiata: Penaeoidea) from the central coast of Brazil, collected by the Revizee program, between 19 º and 22 ºS, Zootaxa 1585, pp. 1-44 : 33-37

Plesiopenaeus armatus ( Bate, 1881)

( Figs. 20–22 )

Aristaeus armatus Bate, 1881: 188 ; 1888: 312–317, pl. 45–46, figs. 1–2.

Aristaeus (Aristaeopsis) armatus - Alcock, 1901: 41.

Plesiopenaeus armatus - Crosnier & Forest, 1973: 294 –296, fig. 99, c–d; Crosnier, 1978: 92 –94, figs. 31 d-e, 32 d–f, 33 b; Pérez Farfante & Kensley, 1997: 50 –52, figs. 19–20; Dall, 2001: 421 –422, fig. 9.

Type locality: Not determined.

Material examined: St.E0520, 13º21.837' S – 38º16.683' W to 13º26.455' S – 38º13.836' W, 2137 m, 20/ VI/2000, 1 female, cl: 38.6 mm, 1 male, cl: 54.6 mm, MNRJ 14576. St. E0525, 20º08.145' S – 38º38.081' W to 20º07.308' S – 38º42.906' W, 1639 m, 28/VI/2000, 1 male, cl: 54.1mm, MNRJ 19523. St. E0548, 21º28,611’S – 39º40,303’W to 21º25,523’S – 39º40,443’W, 1799 m, 1 juvenile male, cl: 22,0 mm, MNRJ 14510. St. E0552, 21º07.493' S – 39º46.423' W to 21º09.541' S – 39º46.079' W, 1694 m, 08/VII/2000, 1 male, cl: 58.2 mm, MNRJ 19519.

Diagnosis: Rostrum sligthly curved upward, with 3 dorsal spines. Cervical carina reaches the middle of carapace. Females with a semioval plate on sternite XII, sternites XI and XIII each with a median carina. Males with a small triangular plate on sternite XII, sternite XI with a median carina, and sternite XIII with a median carina ending in a spine. Abdominal pleurae with small terminal spines. Abdominal somites 3–6 with a median dorsal carina, and with dorsal spines. Petasma with ventral costa approximately of the same size of lateral lobe, with distal extremity curved, but not forming a hook; lateral lobe almost reaches median lobe. Appendix interna semioval with marginal cuspidate setae and with simple setae on base. Appendix masculina of the same length and thinner than appendix interna, with cuspidate setae on inner margin.

Description: Rostrum slightly curved upward, with 3 dorsal spines, with some simple setae on ventral region of rostrum and in front of rostrum spines ( Fig. 20 a). Adrostral and branchiocardiac carina well defined; cervical carina reaches the middle of carapace; antennal, antero-lateral, branchiostegal and gastro-orbital carina present; hepatic carina absent; antennal and branchiostegal spines present ( Fig. 20 a).

Abdominal somites 1–2 with a depression that extends from dorsum to the middle of pleurae; pleurae with marginal setae and small terminal spines; abdominal somites 3–6 with a median dorsal carina, and with dorsal spines ( Fig. 20 a).

Antennal scaphocerite approximately 1.3 X of antennular peduncle ( Fig. 20 a–c).

Right and left mandibles with incisor and molar processes distinct; palp present ( Fig. 20 d, 20e).

Maxillae, maxillipeds as for the family ( Figs. 20 f-g, 21a-c).

First pereopod dactyl approximately 1.6 X of palm; carpus approximately 1.4 X of dactyl; merus approximately 1.5 X of carpus, with a disto-lateral cuspidate setae ( Fig. 21 d).

Second pereopod dactyl approximately 1.5 X of palm; carpus approximately 2 X of dactyl; merus approximately 1.2 X of carpus, with a disto-lateral cuspidate setae ( Fig. 21 e).

Third pereopod dactyl approximately 1.5 X of palm; carpus approximately 2.5 X of dactyl, and of the same size of merus; males with a small spine on coxa ( Fig. 21 f).

Fourth pereopod dactyl approximately 0.5 X of propodus; propodus approximately 0.6 X of carpus; merus approximately 1.4 X of carpus; males with a small spine on coxa ( Fig. 21 g).

Fifth pereopod dactyl approximately 0.5 X of propodus; propodus approximately 0.6 X of carpus; merus approximately 1.4 X of carpus; males with a spine on coxa ( Fig. 21 h).

Females with a semioval plate on sternite XII, sternites XI and XIII each with a median carina ( Fig. 22 a). Males with a small triangular plate on sternite XII, sternite XI with a median carina, and sternite XIII with a median carina ending in a spine ( Fig. 22 b).

Petasma with ventral costa approximately of the same size of ventro-lateral lobe, with distal extremity curved, but not forming a hook; lateral lobe almost reaches median lobe ( Fig. 22 c–d). Appendix masculina semioval with marginal cuspidate setae and with simple setae on base ( Fig. 22 e–f). Appendix interna of the same length and thinner than appendix masculina, with cuspidate setae on inner margin ( Fig. 22 e)

Juvenile male: One juvenile male (cc: 22,0 mm, MNRJ 14510) was found among specimens examined herein. Being a juvenile specimen, its sexual characters are poorly defined, although it is possible to affirm that it is a male for the presence of appendix masculina. Despite sexual characters are very important to separate species of Aristeidae , others characters as carapace and abdominal spines, presence of rudimentary exopods on pereopods, and presence of disto-lateral cuspidate setae on first and second pereopods, were used to affirm that this specimen is P. a r m a t u s.

Distribution: Indian Ocean: Zanzibar; Madagascar; Maldive Islands; Bay of Bengal. Pacific Ocean: Philippines; Japan; Tuamotu Islands; Wallis and Futuna Islands; northeast of Australia; Hawaii. Eastern Atlantic Ocean: off Azores; Madeira; Canary Islands; Cape Verde. Western Atlantic Ocean: Gulf of Mexico ( Pérez Farfante & Kensley, 1997; Dall, 2001).

Depth: 752–5413 m. ( Pérez Farfante & Kensley, 1997; Dall, 2001)

New records: Brazil—from Bahia to Espírito Santo states, between 1639 e 2137 m.

Figures

FIGURE 20. Plesiopenaeus armatus (Bate, 1881). Male, cl: 54.6 mm, MNRJ 14576, a) Habitus; b) Right antenna 1; c) Right antenna 2; d) Right mandible; e) Left mandible; f) Left maxilla 1; g) Left maxilla 2.

FIGURE 21. Plesiopenaeus armatus (Bate, 1881). Male, cl: 54.6 mm, MNRJ 14576, a) Left maxilliped 1; b) Left maxilliped 2; c) Left maxilliped 3; d) Left pereopod 1; e) Left pereopod 2; f) Left pereopod 3; g) Left pereopod 4; h) Left pereopod 5; i) Branchiae position, lateral view (numbers showing the fourth and the thirteenth segments).

FIGURE 22. Plesiopenaeus armatus (Bate, 1881). Female, cl: 55.4 mm, MNRJ 19523, a) Sternum (numbers showing the eleventh and thirteenth sternites). Male, cl: 54.6 mm, MNRJ 14576, b) Sternum (numbers showing the eleventh and thirteenth sternites); c) Right petasma, anterior; d) Right petasma, posterior; e) Right appendix interna; f) Right appendix interna and appendix masculina; g) Left uropod; h) Telson.