Coronarctus dissimilis Gomes-Júnior, Santos, da Rocha, Santos & Fontoura, 2020

Trokhymchuk, Roman, Schmidt-Rhaesa, Andreas, Utevsky, Serge, Kristensen, Reinhardt Møbjerg & Kieneke, Alexander, 2024, Towards a better understanding of deep-sea tardigrade biogeography: numerous new records from the Southern Ocean, Zootaxa 5543 (1), pp. 1-39 : 14

Coronarctus dissimilis Gomes-Júnior, Santos, da Rocha, Santos & Fontoura, 2020

N= 1 specimen: female occurrence: ANDEEP-SYSTCO; 2,981 m bsl. Fig. 6 ; Supplementary Table 1.2

Short description

Large female (273 µm, n=1) with claw heteromorphy ( Fig. 6A ). On the dorsal side a median cirrus is placed close between the posterior edges of the secondary clavae ( Fig. 6B ). Edges of secondary clavae are also clearly visible on the ventral side ( Fig. 6C, C 2 ). Both external and internal claws are with accessory spines on each leg ( Fig. 6B, D ). The presence of gonopore and seminal receptacles allows us to be secure with sex determination.

Remarks

C. dissimilis is recognisable by the secondary clavae shape and median cirrus placed on the posterior end of secondary clavae. This representative exhibits claw heteromorphy and accessory spines as in the original description of Gomes-Júnior et al. (2020).

Figures

FIGURE 2. Absolute abundances of Tardigrada from all 130 analysed core samples of expeditions ANDEEP-1 to 3 and ANDEEP-SYSTCO to the Southern Ocean plotted against depth. Samples were taken at different working areas in the Cape Basin, in the Lazarev Sea, in the Weddell Sea, in the Ona Basin, and at different working stations in the Drake Passage

FIGURE 6. Genus Coronarctus. A Coronarctus dissimilis, female, light microscopy (DIC), ventro-sagittal view. B Coronarctus dissimilis, female, light microscopy (DIC), head, dorsal view, note leg I accessory spines on the external and internal claws (arrowheads). C Coronarctus dissimilis, female, light microscopy (DIC), head ventral view. C2 Coronarctus dissimilis, female, light microscopy (DIC), head ventral view, secondary clava indicated. D Coronarctus dissimilis, female, light microscopy (DIC), leg IV, note leg IV accessory spines on the both external and internal claws (arrowheads). E Coronarctus tenellus, male, light microscopy (DIC), ventral position. F Coronarctus tenellus, male, light microscopy (DIC), head, dorsal view. G Coronarctus tenellus, male, light microscopy (DIC), head, ventral view. G2 Coronarctus tenellus, male, light microscopy (DIC), head, ventral view, secondary clava indicated. H Coronarctus tenellus, light microscopy (DIC), leg IV, note leg IV accessory spines just on the both internal claw (arrowhead). I Coronarctus tenellus, juvenile, light microscopy (DIC), sagittal position, note leg IV with two internal claws and two growing external claws (arrowhead).Abbreviations: bt—buccal tube, cE—cirrus E, mc—median cirrus, pb—pharyngeal bulb, sc—secondary clava, se—leg sensory organ.