Embata laticeps ( Murray, 1905 )

De Smet, Willem H. & Verolet, Michel, 2016, Epibiotic rotifers of Gammarus pulex (L.) (Crustacea, Amphipoda), with descriptions of two new species and notes on the terminology of the trophi, Zootaxa 4107 (3), pp. 301-320 : 315

Embata laticeps ( Murray, 1905)

( Figs 10 , 11 )

Among the rotifers occurring on G. pulex , Embata laticeps was the most abundant. Eggs, tapering to a small knob at one of the poles ( Fig. 10 D), were numerous as well. The spurs were rather short and stumpy compared to freeliving specimens as noted by Donner (1964). The trophi ( Fig. 11 ) have two large plus one smaller major teeth (left/ right: 2+1/1+2, N=10), 13–14 proximal minor teeth and 19–20 distal minor teeth. At the transition of head and shaft, the major teeth show a pore and they are laterally accompanied by short vestigial teeth. The number of major teeth agrees with the data based on LM ( Murray 1905; Donner 1964, 1965; Kutikova 2005). Studying the trophi of the species by SEM, Melone et al. (1998) found a slightly different configuration with two large and one minor teeth, 15–16 proximal minor teeth and 21 distal minor teeth.

Measurements. Body length, trochal disc retracted (N=5) 546−643 µm, spur 17−19 µm; trophi (N=5; l × w) 21.0−23.2 × 24.6−27.0 µm; egg (N=5; l × w) 150−158 × 56−70 µm.

Distribution and ecology. Embata laticeps is known from Europe, America and the Oriental region ( Segers 2007; Jersabek & Leitner 2013). It has been reported free-living among submerged vegetation (e.g. Murray 1905; Donner 1964, 1970; Koste 1976), bed sediments of mountain gravel stream ( Schmid-Araya 1993a, b), epizoic on insects, insect larvae and their casings ( Murray 1905; Koste 1976; Schmid-Araya 1993a), and the crustaceans Asellus aquaticus ( Bartoš 1951) , G. p u l e x ( Donner 1964) and Cardina ensifera ( Fernandez-Leborans et al. 2007). Free-living specimens ( Donner 1970) and epibionts on G. pulex ( Donner 1964) were found feeding on diatoms.

Figures

FIGURE 10. Embata laticeps, habitus. A. lateral, corona retracted; B. extended corona, dorsal; C. foot with spurs; D. egg.

FIGURE 11. Embata laticeps, SEM photographs of trophi. A. frontal; B caudal. Scale bar: 10 µm.