Heterolepidoderma famaillense Grosso & Drahg, 1991

Garraffoni, André R. S. & Melchior, Marina P., 2015, New species and new records of freshwater Heterolepidoderma (Gastrotricha: Chaetonotidae) from Brazil with an identification key to the genus, Zootaxa 4057 (4), pp. 551-568 : 559

Heterolepidoderma famaillense Grosso & Drahg, 1991

( Figs. 7–8 ; Tab. 3 )

Localities. Brazil: cities of Diamantina, São Gonçalo do Rio Preto and Santo Antônio do Itambé, state of Minas Gerais. Reported for the first time in Brazil.

Material. Photographs of four specimens (adults), collected on 29/May/ 2009 in the city of Diamantina, Brazil, available at the Museum of Zoology, University of Campinas, Brazil, under accession numbers ZUEC GCH 13, 14, 15 and 16. Six specimens were examined alive with a compound microscope and are no longer extant.

Elongated body ( Fig. 8 A). Five-lobed head with two pairs of cephalic cilia. Ocellar granules absent. Dorsal scales overlapping; longitudinal rows of keeled scales parallel to the body ( Fig. 7 B–C; 8B). Ventral ciliation as a continuous field of transverse rows covering the entire ventral body surface in the pharyngeal and beginning of the intestinal regions, splitting at the beginning of the intestinal region (U26–27) to form two separate longitudinal bands ( Fig. 8 C). The interciliary area is covered by elliptical keeled scales, with the pharyngeal portion of the field naked ( Fig. 8 C). Ventral terminal scales consists of one pair of larger elliptical keeled scales in the rearmost portion of the ventral region ( Fig. 7 D). Subterminal mouth ( Fig. 7 A). Pharynx with posterior swellings only.

Remarks. The Brazilian specimens exhibit similar ranges to those of Argentinean specimens ( Tab. 3 ), but we were able to find specimens both smaller and larger than those reported by Grosso & Drahg (1991). In terms of morphology, the specimens in our study agree with the original description of H. famaillense previously reported in Argentina, Tucuman, Famaillá (27°03′16″S–65°24′07″W), particularly in the pattern of ventral cilia, and in the distribution and shape of the dorsal keeled scales.

Figures

FIGURE 7. Heterolepidoderma famaillense. DIC photomicrographs: A) Lateral view of head and neck region. B) Ventral view showing the paired keeled scales at the base of the furca. C) Lateral view of trunk region, showing the distribution and shape of scales (white arrow). D) Lateral view of trunk region, showing the distribution and shape of scales. White arrow indicates dorsal keeled scales and black arrow indicates ventral small interciliary scales. Scale bars: 14 Μm.

FIGURE 8. Heterolepidoderma famaillense. SEM photomicrographs: A) Habitus in lateral view. B) Close-up of lateral region of the trunk, showing the keeled scales. C) Ventrolateral view of head and neck, showing the ciliation and shape of scales. Scale bars: A, 20 Μm; B, 2 Μm; C, 10 Μm.