Natatolana hadassae, Paiva & Souza-Filho, 2023

Paiva, Ricardo J. C. & Souza-Filho, Jesser F., 2023, Three new species of the family Cirolanidae Dana, 1852 (Isopoda, Cymothoida) from the shallow Brazilian bathyal, Zootaxa 5319 (1), pp. 1-26 : 14-18

Natatolana hadassae spec. nov.

( Figs 8–12 )

Material examined. Holotype: female, 30.1 mm (dissected and drawn, dissected appendages in alcohol 75%), Potiguar Basin , Rio Grande do Norte, MT 61 station, bottom fish net, 04°48’S, 036°9’W, 400 m, 08 May 2011, MOUFPE 15647 .

Type locality. Brazil, 04°48’S, 036°9’W.

Etymology. Named after Hadassa Vieira de Carvalho Paiva, daughter of the first author.

Diagnosis. Head interocular groove present, incomplete; submarginal furrow absent; dorsal groove absent. Eye unpigmented. Antenna 1 not reaching pereonite 1. Antenna 2 reaching pereonite 3. Pleopod 3–5 exopod with incomplete suture. Pleotelson broader than long, smooth, apex truncated with a subacute medial process, distal margin with 10 RS. Uropod rami lanceolate, apically acute.

Description of female holotype. Body 2.8 times as long as greatest width, dorsal surfaces smooth, widest at pereonite 6, lateral margins slightly convex. Rostral point absent, frontal margin rounded. Eyes separated by about 80% head width, eye unpigmented. Pereonite 1 and coxae 2–3 each with posteroventral angle rounded; coxae 5–7 with entire oblique carina; posterior margins of pereonites 5–7 smooth. Pleon with pleonite 1 not concealed by pereonite 7, pleonites 2–5 posterior margin smooth; pleonite 2 posterolateral angle forming subacute point, not posteriorly produced; pleonite 3 posterolateral margins not extending to pleonite 5 posterior margin, acute; pleonite 4 posterolateral margin acute extended beyond pleonite 5 posterior margin; pleonite 5 with posterolateral angles overlapped by pleonite 4 lateral margins. Pleotelson shorter than anterior width (0.74 times); without longitudinal carina; without dense patch of setae; lateral margins convex, smooth; posterior margin broadly rounded with a middle subacute process, with plumose setae, and a row of 10 RS.

Antenna 1 peduncle articles 1 and 2 distinct, articulated, article 2 0.3 times as long as article 1, article 3 and 4 0.8 times as long as articles 1 and 2 length combined, article 3 1.3 times as long as wide; flagellum moderately inflated, with 20 articles, extending beyond to eye halfway. Antenna 2 peduncle article 4 almost as long as wide, 1.45 times as long as article 3, with 6 short simple setae (distal); article 5 1.8 times as long as article 4, 2.8 times as long as wide, anterodistal angle with cluster of 3 short simple seta; flagellum with 31 articles, extending to pereonite 3.

Frontal lamina 3.75 times longer than greatest width, lateral margins straight, slightly widening anteriorly, not visible in dorsal. Mandible molar process anterior margin with more than 20 flat teeth; without proximal cluster of long simple setae; right mandible spine row composed of 12 spines; palp article 2 with 17 distolateral setae, article 3 with 24 slender setae. Maxillula mesial lobe with 3 large CPS RS; lateral lobe with 10 RS. Maxilla lateral lobe with 2 long simple setae; middle lobe with 16 long simple setae; mesial lobe with 2 simple setae and 12 distal pappose setae. Maxilliped palp article 1 mesial margin without setae, lateral margin without setae; article 2 mesial margin with 6 slender setae, lateral margin with 9 simple setae; article 3 mesial margin with 10 slender setae, lateral margin with 19 slender setae; article 4 mesial margin with 9 slender setae, lateral margin with 12 simple setae; article 5 distal margin to mesial margin with 16 simple setae, lateral margin with 6 simple setae; endite with 5 long CPS and 2 coupling setae.

Pereopod 1 basis 3 times as long as greatest width, superior margin setose, superior distal angle without cluster of setae, inferior margin without setae, inferior distal angle with a cluster of 4 long and slender setae; ischium 1.5 times as long as basis, inferior margin with 12 simple setae, inferior distal margin without setae, superior margin with a middle cluster of 6 simple setae, superior distal margin not produced over merus and with a line of long and slender setae; merus inferior margin with a row of 6 simple setae, superior distal angle produced and reaching 1/2 of carpus, superior margin with a row of both simple and RS; carpus inferior margin with 4 setae, inferior distal angle without setae; propodus 4.1 times as long as wide, inferior margin with 9 simple setae and 2 RS, inferior distal margin with 1 RS and 3 simple setae, superior distal margin with 4 short setae; dactylus 0.5 times as long as propodus. Pereopod 2 ischium inferior margin with 6 long simple setae, inferior distal margin with 6 simple setae, superior distal margin not produced over merus and with a cluster of long and slender setae, mesial margin with a cluster of long and slender setae; merus inferior margin with 1 stout RS, inferior distal margin with 2 RS, superior distal angle produced and reaching 1/4 of propodus, superior margin with a row of both long and simple; carpus inferior margin with 7 stout RS, inferior distal margin with 3 long acute RS; propodus 1.45 times as long as wide, inferior margin without setae, inferior distal margin with 1 short RS and 2 simple setae; dactylus 0.90 times as long as propodus. Pereopod 3 similar to pereopod 2. Pereopods 4–6 similar to each other. Pereopod 7 basis inferior distal angle with a 7 long and plumose setae; superior margin and facial middle line densely setose (plumose setae); basis slightly ovate, 2 times as long as greatest width; ischium 0.5 times as long as basis, 1.5 times as long as wide, widened distally; merus 0.60 times as long as ischium, 1.4 times as long as wide; carpus 0.80 times as long as ischium, 2.4 times as long as wide; propodus 1.2 times as long as ischium, 6 times as long as wide, inferior margin with 4 RS; dactylus 0.45 times as long as propodus.

Pleopod 1 exopod 1.7 times as long as wide, lateral margin convex, distally broadly rounded with distolateral notch, with PMS from entire lateral to distal one-third mesial margin, with ~60 PMS; endopod 1.5 times as long as wide, distally narrowly rounded, with PMS from distal one-third, mesial margin with PMS from distal one-third, endopod with ~40 PMS; peduncle 0.4 times as wide as long, mesial margin with 5 coupling setae. Pleopod 2 exopod with ~90 PMS, endopod with ~30 PMS. Pleopod 3 exopod with incomplete suture, with ~100 PMS, endopod with ~20 PMS. Pleopod 4 exopod with incomplete suture, with ~80 PMS, endopod with ~20 PMS. Pleopod 5 exopod with incomplete suture, with ~35 PMS from distal two-third, endopod with 7 PMS distally. Pleopods 2–5 endopod distal margin with rounded.

Uropod peduncle ventrolateral margin with 7 PMS, posterior lobe 0.90 times as long as endopod; rami slightly shorter than pleotelson, lateral, distal and mesial margin lined with long PMS. Endopod apically acute; lateral margin convex, without prominent excision; mesial margin almost straight. Exopod not extending beyond endopod, 4.4 times as long as greatest width, apically acute; lateral and mesial margin straight, lateral margin with 6 RS.

Distribution. Known only from the type locality, Potiguar Basin, Rio Grande do Norte ( Brazil), at 400 m depth ( Fig. 7 ).

Remarks. Considering the Natatolana species known from the Atlantic Ocean and Mediterranean Sea, Natatolana hadassae spec. nov. is most similar to Natatolana caeca ( Dollfus, 1903) , Natatolana gracilis Hansen, 1890 , and Natatolana imicola ( Dollfus, 1903) due to its unpigmented eyes. However, the new species differs from N. caeca by the incomplete (vs. complete) interocular furrow, antenna 2 reaching the middle of pereonite 3 (vs. reaching the posterior margin of pereonite 2), oblique groove present (vs. absent) in all the coxae, posterolateral margin of pleonite 4 subacute (vs. rounded), ischium of pereopod 3 as produced (vs. less produced) as those of pereopods 1–2, and distal margin of the pleotelson with 10 distal RS (vs. 8 RS).

Natatolana hadassae spec. nov. can be distinguished from N. gracilis , which has also been also recorded from Brazilian waters, by the following combination of characters: ventrolateral margin of the head with a distinct depression (vs. no depression), posterolateral margin of pleonite 3 subacute (vs. rounded), frontal lamina 3.5 times longer than wide, with subparallel lateral margins widening to a rounded apex (vs. frontal lamina 3.1 times longer than wide, with concave lateral margins narrowing to a subacute apex), pereopods 1–7 more setose than in N. gracilis , especially the basis and ischium, pereopod 7 with well-marked medial carina (vs. poorly-defined medial carina), and uropod of the exopod with subacute (vs. rounded) apex.

Natatolana hadassae spec. nov. can be distinguished readily from N. imicola by the fact that pleonite 1 is not concealed by pereonite 7 (vs. almost concealed by pereonite 7), posteroventral angle of pleonite 4 and coxa 7 acute (vs. slightly rounded), and exopods of pleopods 3–5 with poorly developed (vs. strongly developed) sutures.

Figures

FIGURE 7. Map showing distribution of the species: D. brucei (= circle), Dolicholana ivanyae spec. nov. (= square), Natatolana hadassae spec. nov. (= star) and Politolana cleoniceae spec. nov.(= pentagon).

FIGURE 8. Natatolana hadassae spec. nov., Holotype, female, 30.1 mm, (MOUFPE 15647). A = habitus dorsal view; B = habitus lateral view. C = Frontal lamina; D = Pleontelson; E = Pleonites 1–5. Scale bars: A–B = 5 mm; C–E = 2 mm.

FIGURE 9. Natatolana hadassae spec. nov., Holotype, female, 30.1 mm, (MOUFPE 15647). A–B = Maxilla 1–2; C= Antenna 1; D = Antenna 2; E = Maxilliped; F = Mandible. Scale bars = 2 mm.

FIGURE 10. Natatolana hadassae spec. nov., Holotype, female, 30.1 mm, (MOUFPE 15647). A–D = Pereopods 1–4. Scale bars = 2 mm.

FIGURE 11. Natatolana hadassae spec. nov., Holotype, female, 30.1 mm, (MOUFPE 15647). A–C = Pereopods 5–7. Scale bars = 2 mm.

FIGURE 12. Natatolana hadassae spec. nov., Holotype, female, 30.1 mm, (MOUFPE 15647). A–E = Pleopods 1–5; F = Uropod. Scale bars = 2 mm.