Echiniscus canadensis Murray 1910

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 : 7

Echiniscus canadensis Murray 1910

I observed several morphotypes among the 2,712 specimens examined ( Fig. 3 ). Typical appendages (no lateral filaments, dorsal filaments at position C or dorsal spines at position D; Table 4 and Fig. 3 ) ( Ramazzotti & Maucci 1983) were observed in 92% of the total specimens. Overall, eight morphotypes were distinguished ( Fig. 4 ): (i) lacking one dorsal filament at position C (1.3% of all specimens analyzed), (ii) lacking dorsal filaments at C (0.3%), (iii) lacking one dorsal filament at B and dorsal spine at D (0.3%), (iv) lacking dorsal spines at D and one dorsal filament at C (0.3%), (v) lacking dorsal filaments at C and one dorsal spine at D (0.2%), (vi) lacking one dorsal spine at D (1.4%) (morphotype only found in juvenile specimens), (vii) no dorsal spines at D (4%) (morphotype only found in juvenile specimens) and (viii) no dorsal appendices (0.2%) (this morphotype may be easily mistaken for Echiniscus dearmatus Bartos 1935 but Ramazzotti and Maucci (1983) considered it a synonymy of Echiniscus canadensis ). Several of these morphotypes can be found mixed within the same sample. Once again, I discerned three size categories for blumi sculpture design. I also detected some specimens with two spurs at the base of the external claws of the fourth pair of legs. Mean body size was 412 μm (SD 110), range 242 to 880 μm. The species has been cited for Europe, America and Africa. In the Iberian Peninsula, it has been recorded for Portugal ( Da Cunha 1941; Maucci & Durante Pasa 1984, 1985) and Spain ( Rodríguez Roda 1949; Maucci & Durante Pasa 1984). Echiniscus canadensis was collected at 35 sampling points (Table 3), in all habitats but LT.

Figures

FIGURE 3. Morphological variability found in Echiniscus canadensis. Percentages are provided for each morphotype. Arrows indicate missing appendages. * Morphotype found also in juveniles. ** Morphotype found only in juvenile specimens.

FIGURE 4. Morphological variability found in Echiniscus mediantus. Percentages are provided for each morphotype. Arrows indicate missing appendages.