Macrobiotus richtersi Murray 1911

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 : 23

Macrobiotus richtersi Murray 1911

I have isolated 1,378 specimens and 678 eggs from all habitats studied. Cuticle is smooth, pores could not be distinguished in any of the specimens examined. Strong buccal armature in all but 5% of the samples analyzed, where the anterior band of teeth was weak and thus not easily visible. A strong posterior band of teeth is present and the transverse crest system is clearly visible in all specimens. I observed irregular margins on lunules in the fourth pair of legs; these could be old individuals according to Ramazzotti & Maucci (1983). Free-laid eggs had conic-shaped processes and reticulated surface. Inside several specimens I have found rotifers (from Belloidea), nematodes (from Dorylaiminal and Wilsonema species), and other tardigrades (from Hypsibiidae type: Hypsibius , Ramazzottius and/or Diphascon species). The body size range was 275 to 1914 μm, mean 889 μm (SD 331). The species is considered cosmopolitan ( McInnes 1994). In the Iberian Peninsula, it has been recorded for Andorra ( Lewin Osorio 1984; Maucci & Durante Pasa 1984), Portugal ( Da Cunha 1948; Fontoura 1981; Maucci & Durante Pasa 1984, 1985), and Spain ( Rodríguez Roda 1946, 1952; Lewin Osorio 1984; Maucci 1991), but it is the first record for Madrid ( Table 2 ). Macrobiotus richtersi was collected from 54 sampling points (Table 3).