Tectovalopsis potiguara Souza-Filho, Guedes-Silva & Andrade 2024, sp. n.
Creators: name: Souza-Filho, Jesser F.
name: Guedes-Silva, Elkênita
name: Andrade, Luiz F.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Alicellidae
Tectovalopsis
Tectovalopsis potiguara

description: Tectovalopsis potiguara Souza-Filho, Guedes-Silva & Andrade sp. n.
(Figures 6–10)
Material examined
Holotype female, 23 mm, Potiguar Basin, MT 71, initial trawl coordinates 4.4405°S, 36.4308°W, final trawl coordinates 4.4905°S, 36.4026°W, Rio Grande do Norte state, Brazil, initial depth 937 m, final depth 1074 m, 5 May 2011, R / V Seward Johnson col. (MOUFPE 20190).
Type locality
Slope of Rio Grande do Norte state, north-eastern Brazil, between 4.4405°S, 36.4308°W and 4.4905°S, 36.4026°W.
Diagnosis
Lateral cephalic lobe weakly truncate. Antennal sinus shallow. Left mandible incisor with 5 teeth, lacinia mobilis large and strongly toothed. Coxa 1 apically rounded, tapering distally. Gnathopods 1–2 ischium and carpus longer than propodus. Gnathopod 1 palm acute and serrate, defined by a long robust seta. Gnathopod 2 palm strongly acute and serrate, with a weakly excavated, inner margin with 3 robust setae on palmar corner. Epimeron 2 posteroventral corner as a spine, ventral margin bearing robust setae. Urosomite 1 with a dorsal spine. Urosomite 3 with 2 dorsal robust setae on each side. Telson about 80% cleft.
Description
Based on female holotype, 23 mm, MOUFPE 20190. Body as in Figure 6. Head (Figure 7a) about 1.4× deeper than long. Antenna 1 (Figure 7b) accessory flagellum long, 8-articulate; flagellum article 1 with a dense row of callynophores. Antenna 2 (Figure 7c) weakly setose, peduncle article 4 slightly longer than article 5. Upper lip (Figure 7d) apically setose. Lower lip (Figure 7e) setose. Mandibles (Figure 7f–g) right incisor with 3 blunt teeth, lacinia mobilis small and toothed, molar weakly triturative and setulose, accessory setal row with 14 robust multicuspidate setae; palp 3-articulate, article 3 about 3.1× longer than broad, last 2/3 of mesial margin setose. Maxilla 1 (Figure 7h) inner plate with 15 plumose setae; outer plate apical margin with 11 robust setae, 10 being multicuspidate and 1 smooth; palp 2-articulate, article 2 with numerous short slender and robust setae apically. Maxilla 2 (Figure 7i) plates subequal and setose. Maxilliped (Figure 7j) inner plate with plumose setae, apex with 3 short robust setae; outer plate mesial margin with row of short robust setae, bearing apical plumose setae; palp article 4 about half the length of article 3, bearing a short apical nail.
Coxa 1 (Figure 8a) reduced, mostly covered by coxa 2. Coxa 2 (Figure 8b) broadening distally, with 9 setae. Coxa 4 (Figure 9b) posterior margin strongly excavate. Coxae 5–6 (Figure 9c–d) bilobate. Gnathopod 1 (Figure 8a) basis anterior margin with a row of long setae; ischium elongated; carpus about 1.3× longer than propodus; propodus with facial rows of setae; palm bearing 2 short robust setae near corner; dactylus reaching palmar corner, outer margin with a distal seta. Gnathopod 2 (Figure 8b) ischium elongated, with a posterodistal blunt projection; carpus about 1.2× longer than propodus; propodus with facial rows of setae; dactylus outer margin with a distal seta. Pereopods 3–4 (Figure 9a–b) similar in shape, basis slender, merus longer than carpus; carpus subequal to propodus; propodus posterior margin with sets of short robust setae; dactylus bearing a nail. Pereopods 5–6 (Figure 9c–d) basis posterodistal corner produced as a rounded lobe; merus–propodus subequal in length. Pereopod 7 (Figure 9e) basis posterodistal corner produced as a rounded lobe; carpus longer than merus and propodus.
Epimeron 1 (Figure 10a) posteroventral corner rounded. Epimera 2–3 (Figure 10b–c) posteroventral corner as a spine. Urosomites 1–3 (Figure 10d–f) ventral apex produced as a short spine. Uropod 1 (Figure 10g) peduncle 1.2× longer than rami, with dorsal and ventral robust setae, distolateral corner with a stronger seta; rami subequal, with several marginal robust setae. Uropod 2 (Figure 10h) peduncle subequal to outer ramus, about 0.8× the length of the inner ramus; inner ramus 1.2× longer than outer. Uropod 3 (Figure 10i) peduncle about half the length of the rami; inner ramus subequal to outer, with some proximal plumose setae and distal short robust setae; outer ramus article 1 with short robust setae, article 2 about 7% the length of the first article. Telson (Figure 10j) apex bifid, each lobe with 1 plumose and 2 robust subapical setae, bearing 2 plumose and 1 robust dorsolateral setae and sparse robust setae.
Etymology
Derived from the type locality, the Potiguar basin (Rio Grande do Norte state).
Distribution and bathymetry
Known only from the type locality (slope of Rio Grande do Norte state, north-eastern Brazil, between 4.4405°S, 36.4308°W and 4.4905°S, 36.4026°W), between 937 and 1074 m deep (Figure 23).
Remarks
Tectovalopsis has six species; five of them are known from North Pacific thermal vents (13° N), Hess Guyot, Jasper Seamount, and off south-west Mexico, between 706–2884 m (J.L. Barnard and Ingram 1990). The only exception is T. ruffoi (Serejo and Wakabara, 2003), which was described from South Atlantic Ocean, south-eastern Brazil (19.01°S, 37.78°W), between 1500 and 1575 m (Serejo and Wakabara 2003).
Tectovalopsis potiguara sp. n. resembles T. ruffoi in presenting the following: antennal sinus shallow; left mandible lacinia mobilis large and toothed; maxilliped inner plate with 3 short robust apical setae; gnathopods 1–2 ischium and carpus longer than propodus, palms acute; and telson apex bifid, with 2 robust subapical setae. However, the new species differs from T. ruffoi by the following characters (characters of T. ruffoi in parentheses): mandible palp article 3 elongate (shortened); coxa 1 mostly covered by coxa 2 (not covered); gnathopod 1 palm with 2 robust setae near corner (1 robust seta); urosomite 1 with a large dorsal spine (small); uropod 1 peduncle 1.2× longer than rami (as long as rami).
Also, T. potiguara sp. n. is similar to T. nebulosus J.L. Barnard and Ingram 1990, from Baja California (north Pacific Ocean) due to gnathopod 2 palm strongly acute, epimera 2–3 posteroventral corner as a spine, urosomite 1 with simple dorsal keel, uropod 3 not shortened, and telson apex bifid. However the new species can be distinguished from T. nebulosus by the following characters (characters of T. nebulosus in parentheses): left mandible incisor with 5 teeth (4); maxilla 2 inner plate subequal to outer (distinctly smaller); gnathopod 1 ischium subequal to propodus in length (longer); epimeron 1 posteroventral corner rounded (with a short spine); epimeron 2 lacking facial robust setae (with facial robust setae); urosomite 2 dorsally smooth (with a moderate dorsal tooth).
description: Published as part of Souza-Filho, Jesser F., Guedes-Silva, Elkênita & Andrade, Luiz F., 2024, Four new species and two new records of deep-sea Amphipoda (Crustacea: Peracarida) from Potiguar Basin, north-eastern Brazil, pp. 1615-1655 in Journal of Natural History 58 (41 - 44) on pages 1624-1630, DOI: 10.1080/00222933.2024.2374404, http://zenodo.org/record/13758699