Notopoma teresae, Souza-Filho & Serejo, 2014

Souza-Filho, Jesser F. & Serejo, Cristiana S., 2014, On the phylogeny of Ischyroceridae (Amphipoda, Senticaudata, Corophiida), with the description of a new genus and eight new species from deep-sea Brazilian waters, Zoological Journal of the Linnean Society 170 (1), pp. 34-85 : 71-75

NOTOPOMA TERESAE SP. NOV. ( FIGS 25–27 )

Material examined

Holotype: Male (1.77 mm), OCEANPROF II, #44, Campos Basin, Rio de Janeiro, Brazil, 22°11′32.4″S, 39°54′45″W, 1 July 2003, 749 m, MNRJ 21239 .

Paratypes: One male, OCEANPROF I, #79, Campos Basin , Rio de Janeiro, Brazil, 22°20′40.26″S, 40°00′35.1″W, 26 December 2002, 775 m, MNRJ 21238 . One female (dissected and drawn), Campos Basin, Rio de Janeiro, Brazil, 22°11′32.4″S, 39°54′45″W, 1 July 2003, 749 m, MNRJ 21239 .

Etymology

Named in honour of Dr Maria Teresa Valério-Berardo, in recognition of her contribution to the taxonomy of Brazilian Amphipoda .

Type locality

Campos Basin, Rio de Janeiro, Brazil.

Diagnosis

Head eyes present; rostrum subequal to lateral cephalic lobes. Antenna 1 stout, setose, longer than pereonites 1–6 together; article 2 slightly shorter than article 3; flagellum with two articles; flagellum article 1 with few aesthetascs; accessory flagellum absent. Gnathopod 1 propodus palm acute, serrate, and with short and long pappose setae; dactylus not reaching end of palm. Gnathopod 2 carpochelate; basis anterior margin slightly concave and smooth; carpus enlarged, with one large posterodistal process very produced forward, with a middle tooth; propodus 1.9 times as long as wide; propodus posterior margin straight; dactylus slightly shorter than propodus, with one marginal tooth. Pleopod 3 absent. Telson wider than long and weakly cleft.

Description

Based on holotype male (1.77 mm), MNRJ 21239. Head, anteroventral margin strongly recessed; eyes present; rostrum subequal to lateral cephalic lobes. Antenna 1 stout, setose, longer than pereonites 1–6 together; article 2 slightly shorter than article 3; flagellum with two articles; flagellum article 1 with few aesthetascs; accessory flagellum absent. Antenna 2 peduncle article 4 setose, 1.3 times as long as article 5; flagellum with three articles. Mandible palp article 3 shorter than article 2, spatulate, with long setae medially and distally; molar triturative; lacinia mobilis present; right mandible, incisor with six teeth; setal row with two setae; left mandible incisor with five teeth; setal row with four setae. Maxilla 1 inner plate short, with many long marginal setae; outer plate with seven robust setae; palp with four distal robust setae; palp with one facial pappose seta. Maxilla 2 outer plate longer than inner plate; with a row of pappose medial and distal setae. Lower lip inner lobes present; mandibular process well developed. Maxilliped inner plate suquadrate, with two short and robust setae along distal margin and one subdistal short and robust seta; outer plate ovate, with three medial to distal robust setae and two distal robust pappose setae; palp articles 1–3 with long pappose setae along inner margin; palp article 2 2 × length of article 1; palp article 4 with one distal robust seta as long as article 4 length.

Coxae wider than long. Gnathopod 1 subchelate, carpus lobate and shorter than propodus; palm acute, serrate, and with short and long pappose setae; dactylus not reaching end of palm. Gnathopod 2 carpochelate; basis 1.3 times longer than broad; basis anterior margin slightly concave and smooth; carpus enlarged, with one large ventrodistal process very produced forward, with a middle tooth; propodus 1.9 times as long as wide; propodus posterior margin straight; dactylus slightly shorter than propodus, with one marginal tooth. Pereopod 3 basis subovate; merus 1.1 times as long as wide, with anterodistal angle produced; dactylus acute and shorter than propodus. Pereopod 4 similar to pereopod 3, but merus 1.6 times as long as wide. Pereopod 5 basis ovate; merus with anterior and posterior margin produced; propodus triangular, short; carpus longer than merus; dactylus with two accessory spines. Pereopod 6 thin, basis subrectangular; merus and carpus with anterior and posterior margin produced; dactylus with two accessory spines. Pereopod 7 similar to pereopod 6, except for basis broad with posterior margin rounded.

Pleonites with lateral ridges. Pleopod 1 large and biramous. Pleopod 2 biramous, inner ramus 1-articulate, about 1.5 times the length of article 1 of outer ramus. Pleopod 3 absent. Uropod 1 peduncle 1.3 times longer than outer ramus; rami denticulate distally, with one robust seta and one pappose seta; inner ramus with one distal robust and pappose seta; outer margin of outer ramus denticulate, with a row of short robust setae. Uropod 2 uniramous; ramus outer margin denticulate, with one long seta distally. Uropod 3 uniramous, almost as long as ramus of uropod 2; peduncle broad; ramus short with two short upturned spines. Telson wider than long and weakly cleft.

Sexually dimorphic characters

Based on paratype female (1.9 mm), MNRJ 21238. Very similar to male, but with gnathopod 2 subchelate, basis stout, 2 times longer than wide, with a few long setae on the anterior margin; merus triangulate, produced; propodus ovate, longer than carpus, with long setae along the palm. Pereonite 5 is wider than others.

Tube

Unknown.

Remarks

Notopoma teresae sp. nov. is similar to N. africana Lowry & Berents, 1996 and N. fallohidea ( Lowry, 1981) in the long thin antennae, about half the body length, and the dactylus of gnathopod 2 more than half the propodus length. It also resembles N. africana in having a slender palp of the mandible and seven robust setae on the outer plate of maxilla 1; however, N. teresae sp. nov. can be distinguished from both species by the 2-articulate flagellum of antenna 1, the distoventral process of gnathopod 2 more produced anteriorly, and a more inflated propodus. Furthermore, N. teresae sp. nov. differs from N. africana by the presence of eyes, absence of pleopod 3, the inner ramus of uropod 3 about two-thirds the outer ramus length, and the telson weakly cleft.

Geographic distribution

South-western Atlantic: Campos Basin, Rio de Janeiro, Brazil.

Figures

Figure 25. Notopoma teresae sp. nov. Holotype: male (1.77 mm), OCEANPROF II, #44, 1 July 2003, 749 m, MNRJ 21239. Scale bars: 0.05 mm.

Figure 26. Notopoma teresae sp. nov. Holotype: male (1.77 mm), OCEANPROF II, #44, 1 July 2003, 749 m, MNRJ 21239. Scale bars: 0.1 mm.

Figure 27. Notopoma teresae sp. nov. Holotype: male (1.77 mm), OCEANPROF II, #44, 1 July 2003, 749 m, MNRJ 21239. Paratype: female (1.9 mm), 1 July 2003, 749 m, MNRJ 21239. Scale bars: 0.1 mm.