Macromckenziea giambonini, Brandão, 2010

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 : 594

MACROMCKENZIEA SP. CF. MK. GIAMBONINI SP. NOV. ( FIG. 7 )

Material: 6 live specimens. 6 A F ( SNB 0453-0457), ANDEEP III , # 74-6, ZMH K- 41364.

Distribution ( Fig. 7 ): Eastern Weddell Sea, SO, 1040– 1048 m.

Measurements ( Fig. 7 ): A F, RV, L 1.64-1.81 mm, H 0.72–0.80 mm.

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(0/5.5), 4(.2/.1c:3), 5(0/.1,1c:1.3c), 6(0/0:4c,1s). Mandible 1(0/ 5t,+5.1.), 2(0/.2), exopodite (0/0:5), 3(0/5:1), 4(5/4), 5(.2./0:3). Maxilla I vibratory plate (1re,~17), palp 1+2(4/0), 3(0/0:5). Appendage V F 1, exopodite (.3./0:4), 2, 3, 4(0/1), 5(0/0:3). Appendage VI 1(0/.1), 2(.1/.1.1.1), 3(0/.1), 4(0/.1), 5(0/.1), 6(0/0:2c,1). Appendage VII 1+2(.1/.1), 3(0/ 1), 4(0/1), 5(0/1), 6(0/0:1.1r,1). Furca 1(0/0:1.2r).

Remarks: The females of this species are morphologically very similar to Mk. giambonini and also occur at around 1000 m depth on the continental slope of the eastern Weddell Sea, but the considerably larger size (black circles in Fig. 7 ) prevents referral to Mk. giambonini . As in the case of the informal groups Mh. turbida and Mh. tensa-opaca , it may be that both of these species can only be distinguished by the hemipenis. As the males are unknown for both populations, the second one is left in open nomenclature.

Figures

Figure 7. Geographical distribution and height ¥ length scatter plot of valves of Macromckenziea glacierae Maddocks, 1990, Macromckenziea giambonini sp. nov., and Macromckenziea sp. cf. Mk. giambonini. In the scatter plot of Mk. glacierae: F+J, females and juveniles; M, males; EW, eastern Weddell Sea; WW, western Weddell Sea; Mk. sp. Maddocks, Macromckenziea sp. 3 from Maddocks (1990).