Lepidochaetus zelinkai (Grünspan, 1908)
Most likely ID: n.a.
Synonym: Chaetonotus zelinkai
Sampling location: Simmelried
Phylogenetic tree: Lepidochaetus zelinkai
Diagnosis:
- body slender, elongated, posterior end narrowed
- length 200–310 µm
- head hammer-shaped, five-lobed
- cephalion present
two pairs of dorsal setolae, posterior ones on special oval scales - toes 30–39 µm long with thin adhesive tubes (20–33 µm)
- dorsal 11–13 longitudinal rows of oval or elliptically scales with a bulged anterior margin
- dorsal scales with simple spines, 30–35 µm long
- ventral 7 longitudinal rows of oval scales with short, simple spines
- at posterior end 7 elongated spines each with a secondary spine, 30–85 µm long
- dorsal anal region covered with roundish, spineless scales
So far I have only found Lepidochaetus zelinkai in the uppermost mud layer in the Simmelried. Lepidochaetus zelinkai can be recognized even at low magnification by the 7 elongated terminal spines (s. fig. 9). Three pairs arise laterally and one spine arises dorsally in the middle of the anal region. The dorsal scales have a raised anterior margin and a distal indentation, which can only be recognized on isolated scales (s. fig. 6). The ventral scales are smaller versions of the dorsal scales (s. figs. 7 a-b and 8). However, the simple spines are shorter here.
Fig. 1 a-c: Lepidochaetus zelinkai. L = 204 µm (without terminal spines). A freely swimming specimen from dorsal (a, b) and from right (c). Obj. 40 X.
Fig. 2 a-b: Lepidochaetus zelinkai. L = 215 µm (without terminal spines). A second freely swimming specimen from dorsal. Obj. 40 X.
Fig. 3 a-c: Lepidochaetus zelinkai. L = 238 µm (without terminal spines). A third freely swimming specimen from dorsal. Obj. 40 X.
Fig. 4: Lepidochaetus zelinkai. The dorsal scales covering the head in detail. Obj. 100 X.
Fig. 5 a-b: Lepidochaetus zelinkai. The dorsal scales of a slightly squashed (a) and squashed specimen (b). Note the bulged anterior margin of the scales (BM). Obj. 100 X.
Fig. 6: Lepidochaetus zelinkai. A detached dorsal scale. Obj. 100 X.
Fig. 7 a-b: Lepidochaetus zelinkai. L = 304 µm (without terminal spines). Two focal planes from ventral. Obj. 100 X.
Fig. 8: Lepidochaetus zelinkai. The ventral scales in detail. Obj. 100 X.
Fig. 9: Lepidochaetus zelinkai. The elongated, terminal spines, each with a small secondary spine (arrows). Obj. 100 X.