Xenotrichula intermedia Remane, 1934

Todaro, M. Antonio & Rocha, Carlos E. F., 2004, Diversity and distribution of marine Gastrotricha along the northern beaches of the state of São Paulo (Brazil), with description of a new species of Macrodasys (Macrodasyida, Macrodasyidae), Journal of Natural History 38 (13), pp. 1605-1634 : 1629-1630

Xenotrichula intermedia Remane, 1934

( figure 6A )

Remane, 1934: 477–478.

Adult specimens with total body length up to 180 µ m (range 160–180, N ~8); PhIJ at U24.8; pharynx length up to 41 µ m; furca length up to 25 µ m with adhesive tube up to 11.5 µ m. Widths of head, neck, trunk and furcal base as follows: 30, 25, 40, 18.7 µ m. Sixteen to 20 dorsal and lateral columns of intermedia - type stalked scales, seven columns on each side of the ventral midline; a triangular field of flat scales posterior to the anus; five scales on the inner margin of the furca; cephalion not seen, hypostomion present. Anterior, ventral cirri of virtually equal size, mostly in columns of three to four each per side of the midline of the body; posterior tufts with three to five cirri; three pairs of sensory cirri; very small head palps present; three to four pairs of oral cilia; at least three pairs of elongate sensory cilia. Furca simple type. Anus ventral at U84.5. Adhesive glands near posterior end of the intestine. Protandric then simultaneous hermaphrodite; male copulatory organ unpaired, posteriorly directed, located near the tufts of cirri of the trunk.

Remarks

Metric characteristics of the Brazilian specimen fall within the lower end of the range known for the species.

Ecology

Frequency of occurrence: occasional in sediment of the northern sites, usual in southern sites but apparently absent in locations of the São Sebastião Channel and on Ilhabela. Abundance: prevalent to numerous in sub-littoral, fine sediment of the southern locations, scarce elsewhere.

Distribution

Brazil: Ubatuba: praia Prumirim (l, sl), praia Vermelha (l); São Sebastião: praia de Santiago (sl), praia do Saı´, praia Preta e Conchas. World: cosmopolitan.

Figures

FIG. 6. (A) Xenotrichula intermedia; (B) Xenotrichula sp. 1; (C) Chaetonotus apechochaetus; (D) Chaetonotus atrox; close-up of the ventral anterior region; (E) Chaetonotus dispar; (F) Chaetonotus neptuni; (G) Chaetonotus sp. 1; (H) Chaetonotus sp. 2; (I) Chaetonotus sp. 3; (L) Chaetonotus sp. 4, close-up of the dorsal scales. Nomarski optics. Scale bars: 50 µm (A–C, E–I); 25 µm (D); 10 µm (L).