Macroscapha inaequata, MADDOCKS, 1990

Brandão, Simone N., 2010, Macrocyprididae (Ostracoda) from the Southern Ocean: taxonomic revision, macroecological patterns, and biogeographical implications, Zoological Journal of the Linnean Society 159 (3), pp. 567-672 : 622-632

MACROSCAPHA INAEQUATA MADDOCKS, 1990

( FIGS 34 , 37A–C, 37H–J , 38A–C, 38H–J , 39D, 39H , 40A–G , 41A–C, 41Z, 64G–H )

1979 Macrocyprina sp. nov. 7, Maddocks, 1979, pl. 2.11.

1990?in part Macroscapha inaequata Maddocks, 1990: 99–100 . Numerous figures and plates.

1997 Macroscapha inaequata, Hartmann, 1997: 246– 247 , fig. 104.

Material: 61 live specimens.

2 A F ( SNB 0054), 6 A M ( SNB 0021, 0034, 0052, 0053), 1 A, 1 (A-1), EASIZ II, # 48-107, ZMH K- 40819;

1 A F ( SNB 0752), EASIZ II, # 316, ZMH K- 40821; 1 A M ( SNB 0753), EASIZ II, # 323, ZMH K- 40822; 17 A F, 13 A M ( SNB 0099-DNA 2, SNB 0100-DNA 12, SNB 0580-DNA 287, SNB 0581-DNA 288, SNB 0582- DNA 289), six juveniles, three live specimens ( SNB 0098-DNA 1, SNB 0778-0784), ANDEEP III , 74-6-E; 5 A F, 5 A M ( SNB 0575-0579-DNA 283-286), ANDEEP II , # 74-6-S, ZMH K- 41487.

Distribution ( Fig. 34 ): Recent. Atlantic Sector of the SO, 311-2452 m.

Right valve measurements ( Fig. 34 ): A F L 1.80– 1.94 mm, H 0.70–0.79 mm; A M L 1.80–1.90 mm, H 0.71–0.76 mm; (A-1) L 1.48–1.56 mm, H 0.56– 0.61 mm.

Remarks: Considering the material studied herein, the hemipenis of the only adult male of Mh. inaequata collected from the continental slope (no. 323) presents a more sinuous posterior margin ( Fig. 40A–D ) than that of specimens collected on the shelf, which present a subhemispherical outline ( Fig. 40E ). Variation in hemipenis outline and in the copulatory process (bilobated versus elongated) can also be observed amongst previously studied specimens ( Maddocks, 1990: pl. 92. 3, 92.7). Additionally, the only abyssal record of Mh. inaequata (collected from the Pacific Sector of the SO) involves a teratological specimen of considerably larger size (~ 2.3 mm) and more rectilinear outline than the other specimens ( Maddocks, 1990: 100, graph 47); this record is therefore not considered herein. Consequently, similar to Mk. glacierae and Mh. opaca , I think that Mh. inaequata is most probably a group of closely related species, instead of one species with such a large morphological variation, geographical and bathymetrical distribution.

Adult chaetotaxy: Antenna I 1(0/0), 2(0/.2)+3(.1/.1), 4(.1/.1), 5(.1/.1), 6(.2/.3), 7(0/0:4). Antenna II 1(0/.0-1:1), 2(0/0:1), Exopodite (0/0:2,1r), 3(0/.5-6.4), 4[female (.1r./.1r.1c,2)] [male (.1r./.1r.1c,2mod,1)], 5(0/1c,1:3-4c,1-2), 6(0/0:2c,2-3). Mandible 1(.1/0: 5-6t,+8), 2(0/.2:1), Exopodite (1r,5-7), 3(0/.4:-4), 4(.3.2/.4), 5(0./0:2-3c,2-3). Maxilla I vibratory plate (2strahlen,+16), palp 1(.1/0), 2(.4-5/0), 3(0/0:6). Appendage V 1(0/0:1-2.0-1.1), Exopodite (0/0:7-10), [female 2(0/0), 3(0/0), 4(0/.1), 5(.1./ 0:1c,1)] [male 2(0/2mod,1:1r), 3(0/0:1mod)]. Appendage VI 1(.1-2./0), 2(.2.1./.1), 3(.1/0), 4(.1/0), 5(.1,1r/0), 6(0/ 0:1,2c). Appendage VII 1(0/0:1), 2(.1.1.1/.1.), 3(.1/0), 4(.1/0), 5(.2/0), 6(0/0:2,1mod). Furca (0/0:1,4r).

MACROSCAPHA WALTERAE SP. NOV. ( FIGS 34 , 37K–M , 38K–M , 39E–G, 39J–K, 39P–Q , 40H–P , 41D–I, 412, 42, 64A, 64I–J)

Etymology: In honour of Renate Walter (University of Hamburg) for her valuable technical assistance for three generations of ostracodologists.

Material: 43 live specimens plus 43 valves.

Holotype: 1 A M ( SNB 0745 ) (soft parts in glass slide, valves in micropalaeontological slide), ANDEEP II , #132-2-S, ZMH K-41484 .

Paratypes: 6 A F ( SNB 0047 , 0048 ), 9 A M ( SNB 0051 , 0748 , 0749 , 0750 , 0751 ), 6 (A-1), EASIZ II , # 89, ZMH K-40818 ; 2 A F, 3 (A-1), 6 RV, 7 LV, 5 RLV, 4 V, ANDEEP II , # 132-2-S, ZMH K-41486 ; 1 A M ( SNB 0574 ), 7 RV , 5 LV, 2 RLV, ANDEEP II , # 133-3, ZMH K-41481 ; 1 A M ( SNB 0119 -DNA 22) ANDEEP III , # 121-7, ZMH K-41480 ; 3 A F ( SNB 0421 -DNA 128, SNB 0462-DNA 169, SNB 0611-DNA 318), 3 A M ( SNB 0419 -DNA 126, SNB 0422-DNA 129, SNB 0746), 4 (A-1) ( SNB 0420 -DNA 127, SNB 0612-DNA 319, SNB 0613-DNA 320), three live specimens ( SNB 0799 , 0800 ), ANDEEP III , # 133-2, ZMH K-41485 .

Distribution ( Fig. 34 ): Recent. Weddell Sea, 1123– 2666 m.

Valve measurements ( Fig. 34 ): Holotype, RV L 2.01 mm, H 0.80 mm; LV L 1.96 mm, H 0.80 mm. Paratypes, A L 1.90–2.16 mm, H 0.76–0.88 mm; (A–1) L 1.60–1.72 mm, H 0.62–0.68 mm.

Diagnosis: Carapace fairly large (for the genus); lateral outline subhemispherical to subtriangular with faint dorsal angle; posterior margin rounded. Female appendage V with one short and three medium-sized, terminal setae, medial and ventral ones subequal in length and thickness. Male appendage V very asymmetrical; terminal podomere strongly sclerotized, and pointed at 90° in right appendage, but smoothly curved in left one. Furca very asymmetrical. Hemipenis

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subhemispherical to elongated, strongly sclerotized, with V-shaped copulatory process, maximum height posterior to mid-length. Zenker’s organ with very thin, weakly sclerotized central tube and very large terminal bulb; vas deferens arranged as several loops as long as the Zenker’s organ’s central tube.

Description: Carapace fairly large (for the genus), lateral outline subhemispherical to subtriangular, with faint dorsal angle; posterior margin obtusely rounded; ventral margin fairly straight, anterior margin protruded and narrowly rounded. Vestibules medium-sized, zone of concrescence thin, except by the medium-sized anteroventral region; radial pore canals mostly straight, very few slightly ramified. RV always larger than and overlapping LV.

Podomere IV of antenna I and podomere II of antenna II elongated. Mandible with one conical plus four tricuspidate teeth. Female appendage V with podomere II (= palp podomere I) more than two times longer than podomere III; podomere V with one medial and one ventral, subequal, medium-sized setae, dorsal seta short. Male appendage V strongly asymmetrical, podomere I (basis) with long setae; right appendage with podomere II bearing one long and one short modified setae (= pegs) plus one short seta, and podomere III strongly sclerotized and pointed at 90°; left appendage with podomere II bearing two short modified setae (= pegs) plus one short seta, and podomere III smoothly curved. Podomere II of appendage VI with three long, dorsal setae; podomere VI with one long claw, one medium-sized seta, and one short seta. Reflexed seta of appendage VII long. Furca very asymmetrical, shorter ramus three-quarters as long as longer ramus, suture between rods and terminal setae conspicuous. Hemipenis subhemispherical to elongated, strongly sclerotized; maximum height posterior to mid-length; copulatory process V-shaped. Zenker’s organ with very thin, weakly sclerotized, central tube and very large terminal bulb; vas deferens arranged as several loops as long as the Zenker’s organ’s central tube.

Adult chaetotaxy: Antenna I 1, 2(0/.2), 3(.1/.1.), 4(.1/.1.), 5(.1/.1), 6(.2/.3), 7(0/0:4). Antenna II 1(0/0:1), 2(0/ 0:1), Exopodite (0/0:2,1r), 3(0/6.4), 4[female (.2./.2.1c,3)] [male (.1r./.2r.1c,2mod,1)], 5(0/.1c,1:4c,1), 6(0/ 0:2c,2). Mandible 1(0/ 5t,+5.1.), 2(0/.2:1), Exopodite (0/0:1r,7), 3(0/.4-5:3-4), 4(.4-5/4), 5(0/0:3c,3). Maxilla I vibratory plate(2re,19), palp 1(.1/0), 2(.4/0), 3(0/0:6). Appendage V 1(0/.2.1.1), Exopodite (0/0:3.4-7), [female 2, 3, 4(0/.1) 5(.1./0:1,1)]; [male 2(0/2mod,1:0-1r), 3(0/.1r:1mod)]. Appendage VI 1(.1-2/0), 2(.2.1/.1), 3(.1/.0), 4(.1/0), 5(1,1r/0) 6(0/0:1,2c). Appendage VII 1(0/0:1), 2(.1.1.1/1) 3(.1/0), 4(.1/0), 5(.2/0), 6(0/0:2,1re). Furca 1(0/0:3-4r.1).

Remarks: Genetic distances (marker COI, model of evolution HKY85) amongst specimens of the same station (no. 133-2, average 0.0008) are considerably larger than genetic distances between specimens of different stations – nos 133-2 and 121-11, average 0.0090. Such a picture indicates that the depth or any factor related to it (e.g. water masses) plays an important role in hindering genetic flux. This finding is in accord with Dingle et al. (1990), who found relationships between Atlantic deep-sea ostracod distribution and water masses.

Similarly, genetic distances between specimens of Mh. walterae (Weddell Sea) and Macroscapha sp. aff. Mh. walterae (from the Scotia Sea , see below) are even greater (0.055).

The valve lateral outline of Mh. walterae sp. nov. is very similar to Mh. inaequata , but the former species is larger ( Figs 34 , 37 , 38 ) and displays a more elongated hemipenis, with a shovel-shaped (instead of rod-shaped) copulatory process.

Concerning the lateral outline of the valves (1) Macroscapha atlantica , Mh. heroica , Mh. jiangi , Mh. sinuata , and Mh. turbida , have more sinuous outlines than Mh. walterae ; (2) Mh. gyreae , Mh. inaequalis , Mh. rehmi , and Mh. tensa are more elongated, less high in relation to length; (3) Mh. scotia is more subtriangular, higher in relation to length; (4) Mh. opaca presents a more acute posterior angle; (5) Mh. marchilensis is similar in valve outline to Mh. walterae but the Zenker’s organ of the former species presents a medium-sized (instead of very large) terminal bulb.

Figures

Figure 34. Geographical distribution and height ¥ length scatter plot of valves of Macroscapha inaequalis, Macroscapha inaequata, Macroscapha walterae sp. nov., Macroscapha sp. aff. walterae sp. nov., and Macroscapha sp. (of the informal group Macroscapha turbida). Both records of Mh. inaequata (Maddocks, 1990) from the Pacific Sector of the Southern Ocean are herein considered dubious because they are based on only one female (Ross Sea) and one very large teratological adult of indeterminable sex (south-west Pacific Basin; Maddocks, 1990).

Figure 37. External view of right valves of Macroscapha inaequata Maddocks, 1990, Macroscapha scotia sp. nov., and Macroscapha walterae sp. nov. Macroscapha inaequata Maddocks, 1990: A, adult female (SNB 0752, ZMH K-40821); B, adult male (SNB 0578-DNA 285. ZMH K-41487); H, (SNB 0052); I, (SNB 0053); J, adult female (SNB 0054) (ZMH 40819). Macroscapha scotia sp. nov.: C, paratype A M? (ZMH K-35501); D, holotype adult male (SNB 0739, ZMH K-40820); E, paratype adult male (SNB 0022); F, paratype adult female (SNB 0056); G, paratype adult female (SNB 0741) (ZMH K-40837). Macroscapha walterae sp. nov.: K, holotype adult male (SNB 0745, ZMH K-41484); L, paratype adult male (SNB 0051); M, paratype adult male (SNB 0750); N, paratype adult female (SNB 0048) (ZMH K-40818). Scale bar = 500 Mm.

Figure 38. External view of left valves of Macroscapha inaequata Maddocks, 1990, Macroscapha scotia sp. nov.; and Macroscapha walterae sp. nov. Macroscapha inaequata Maddocks, 1990: A, adult female (SNB 0752, ZMH K-40821); B, adult male (SNB 0578-DNA 285. ZMH K-41487); H, (SNB 0052); I, (SNB 0053); J, adult female (SNB 0054) (ZMH 40819). Macroscapha scotia sp. nov.: C, paratype A (ZMH K-35501); D, holotype adult male (SNB 0739, ZMH K-40820); E, paratype adult male (SNB 0022); F, paratype adult female (SNB 0056); G, paratype adult female (SNB 0741) (ZMH K-40837). Macroscapha walterae sp. nov.: K, holotype adult male (SNB 0745, ZMH K-41484); L, paratype adult male (SNB 0051); M, paratype adult male (SNB 0750); N, paratype adult female (SNB 0048) (ZMH K-40818). Scale bar = 500 Mm.

Figure 39. Appendages V, VI, and VII and furcae of Macroscapha inaequata Maddocks, 1990, Macroscapha rehmi sp. nov., Macroscapha scotia sp. nov., Macroscapha turbida (Müller, 1908), and Macroscapha walterae sp. nov. Macroscapha scotia sp. nov.: A, paratype adult female (SNB 0024); L, M, paratype adult male (SNB 0738), ZMH K-40837. Macroscapha rehmi sp. nov.: B, paratype adult female (SNB 0028); N, O, paratype adult male (SNB 0743); ZMH K-40836. Macroscapha turbida (Müller, 1908): C, adult female (SNB 0348-DNA 85); I, adult male (SNB 0355); R, adult male (SNB 0351-DNA 88); S, adult male (SNB 0347-DNA 84) (ZMH K-41476); T, U, paralectotype (SNB 0747, ZMB 13133). Macroscapha inaequata Maddocks, 1990: D, adult female (SNB 0752, ZMH K-40821); H, adult male (SNB 0753, ZMH K-40822). Macroscapha walterae sp. nov.: E, paratype adult female (SNB 0611-DNA 318); F, J, K, paratype adult female (SNB 0462-DNA 169); G, P, (A-1) male paratype (SNB 0612-DNA 319); Q, paratype (A-1) male (SNB 0613-DNA 320) (ZMH K-41485). A–E, female appendage V; F, appendage VI; G–I, K, furca; J, appendage VII; L–O, R–U, male appendage V; P, Q, (A-1) appendage V. Scale bars = 100 Mm.

Figure 40. Appendages V and hemipenis of Macroscapha inaequata Maddocks, 1990 and Macroscapha walterae sp. nov. Macroscapha inaequata Maddocks, 1990: A, adult male (SNB 0021, ZMH K-40819); B, adult male (SNB 0052, ZMH K-40819); C, adult male (SNB 0099-DNA 2, ZMH K-41487); D, adult male (SNB 576-DNA 283, ZMH K-40822); E, adult male (SNB 0753, ZMH K-40822); F, adult male (SNB 0053, ZMH K-40819); G, adult male (SNB 0579-DNA 286, ZMH K-41487). Macroscapha walterae sp. nov.: H, O, P, paratype adult male (SNB 0745, ZMH K-41484); I, paratype adult male (SNB 0746, ZMH K-41485); J, paratype adult male (SNB 0422-DNA 129, ZMH K-41485); K, N, paratype adult male (SNB 0119-DNA 22, ZMH K-41480); L, paratype adult male (SNB 0051, ZMH K-40818); M, paratype adult male (SNB 0750, ZMH K-40818). A–E, H–M, hemipenis; F, G, O, P, male appendage V; N, copulatory rod of hemipenis. Scale bars = 100 Mm.

Figure 64. Dorsal, ventral, and internal views of Macroscapha inaequata (Maddocks, 1990), Macroscapha rehmi sp. nov., Macroscapha scotia sp. nov., Macroscapha turbida (Müller, 1908), and Macroscapha walterae sp. nov. Macroscapha walterae sp. nov.: A, subfossil paratype (ZMH K-41486); I, J, paratype adult male (SNB 0051, ZMH K-40818). Macroscapha turbida (Müller, 1908): B, C, adult male; D, adult female (ZMH K-41476). Macroscapha scotia sp. nov.: E, paratype adult female, F, paratype adult male (ZMH K-33192); M, N, paratype adult male (SNB 0022, ZMH K-40837). Macroscapha inaequata (Maddocks, 1990): G, H, adult female (SNB 0054, ZMH K-40819). Macroscapha rehmi sp. nov.: K, L, paratype adult female (SNB 0059, ZMH K-40836). A, B, D–F, right and left valve (RLV) dorsal view; C, RLV ventral view; G, I, K, M, LV internal view; H, J, L, N, RV internal view. Scale bar = 500 Mm. The arrows point towards the anterior of the animal.