Macrobiotis cf. hystricogenitus Maucci 1978

Guil, Noemí, 2008, New records and within-species variability of Iberian tardigrades (Tardigrada), with comments on the species from the Echiniscus blumi-canadensis series, Zootaxa 1757, pp. 1-30 : 22

Macrobiotis cf. hystricogenitus Maucci 1978

Smooth cuticle with a fine dot sculpture in the ventral region. Weak buccal armature, showing only a transverse crest system, was observed in the 13 specimens found. Two rod-shaped macroplacoids and a large microplacoid were present within the pharyngeal bulb; first macroplacoid two times as long as the second macroplacoid, and with median constriction. Double-claws with long common tract, short secondary branch inserted to the main branch in a right angle and big lunules, which had smooth margins in the three first pairs of legs ( Fig. 7 A), and big teeth in the fourth pair of legs. All seven specimens from spring collection (found in leaf litter, Retama sphaerocarpa ) showed hystricogenitus double-claws with an additional spur inserted at the same level as the secondary branch (arrows in Fig.7 B); I have considered these specimens as Macrobiotus hystricogenitus since the rest of the morphology corresponded to this species. This additional spur could be considered as particular alterations because they were present only in some legs and with no pattern. Ocular spots were observed in nine specimens, and were not present in four specimens. Mean body size was 886 μm (SD 211), range 550 to 1210 μm. This species has been cited for Europe and Asia. It is the first time the species is recorded for the Iberian Peninsula ( Table 2 ). Macrobiotus hystricogenitus was found only at one site (Table 3), in autumn and in spring.

Figures

FIGURE 7. Double-claw photos from one Macrobiotus hystricogenitus specimen: (A) double-claws from the first pair of leg, typical Macrobiotus hystricogenitus claw morphology, and (B) double-claws from the second pair of legs with an additional spur (arrows). Scale bar = 10 μm.