Heterolepidoderma aff. majus Remane, 1927

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 : 562

Heterolepidoderma aff. majus Remane, 1927

( Figs. 9 ; Tab. 4 )

Localities. Brazil: city of São Carlos, state of São Paulo.

Material. Photographs of two specimens (adults), collected on 13/Jun/ 2015 in the city of São Carlos, Brazil, available at the Museum of Zoology, University of Campinas, Brazil, under accession numbers ZUEC GCH 17 and 18.

Remarks. As reported above, within the genus Heterolepidoderma , only H. mariae sp. nov., H. majus , H. brevitubulatum and H. jureiense have clearly three-lobed heads. The specimens collected in Broa Dam do not exhibit three different shapes of dorsal scales (like H. mariae sp. nov.), or extremely short and slightly bifurcate adhesive tubes (like H. brevitubulatum ), or ventrolateral lamellae (like H. jureiense ). Although we collected sediments at the same site where Kisielewski (1991) found Heterolepidoderma majus , we noticed considerable differences in our two specimens tentatively identified as H. majus . We were not able to clearly observe the keels transforming into short spines that project beyond the edges of posterior scales ( Fig. 8 ); the morphometrical features of our specimens are different from those reported by Kisielewski (1991) ( Tab. 4 ), and the interciliary area of the pharyngeal and beginning of the intestinal regions clearly have small keeled scales. However, a description of a putative new taxon is beyond the scope of the present study because few specimens were studied and more material is needed for a complete description.

*present study; ** Kisielewski (1991) - specimen from São Carlos region, state of São Paulo.

Figures

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.

FIGURE 9. Heterolepidoderma aff. majus. A) Dorsal view of head and neck region. B) Dorsal view of head and neck region, showing the distribution and shape of scales. C) Ventral view showing the cilia and interciliary scales. Scale bars: 25 Μm.

Tables

TABLE 4. Morphometrical features of Heterolepidoderma aff. majus. X = mean; N = number of specimens measured.

Features	Range of X specimens from Brazil*	N	Range of Literature data specimens from Brazil**
Body length	187–195 µm 191	2	130–155 µm 136–200 µm
Length of adhesive tubes	12.5–13 µm 12.8	2	7–11 µm 7–11 µm
Pharynx length	63–67.5 µm 65.3	2	34–40 µm 32–51
Diameter of mouth ring	10–12 µm 10.9	2	6–7 µm 5.5–8
Cephalion length	10–11 µm 10.5	2	11–14 µm -
Cephalion width	22–24 µm 22.9	2	16–27.5 µm -
Total number of longitudinal rows of scales	- -	2	45–49 46–63