Tylomelania hannelorae, Rintelen, Thomas Von & Glaubrecht, Matthias, 2008

Rintelen, Thomas Von & Glaubrecht, Matthias, 2008, Three new species of the freshwater snail genus Tylomelania (Caenogastropoda: Pachychilidae) from the Malili lake system, Sulawesi, Indonesia, Zootaxa 1852, pp. 37-49: 46

publication ID

http://doi.org/ 10.5281/zenodo.183429

DOI

http://doi.org/10.5281/zenodo.5621359

persistent identifier

http://treatment.plazi.org/id/5F2DDF50-FFB9-9334-FF26-FF4B97209B4D

treatment provided by

Plazi

scientific name

Tylomelania hannelorae
status

sp. nov.

Tylomelania hannelorae   sp. nov.

Type material. Indonesia, Sulawesi, Lake Mahalona, loc. 56 -03: Holotype ( Fig. 6 View FIGURE 6. T A; 11.8 mm x 5.5 mm), MZB Gst. 12.114; paratypes ( Fig. 6 View FIGURE 6. T B), MZB Gst. 12.115, n= 3; ZMB Moll. 190713, n= 5.

Etymology. The new species has been named hannelorae   in honour of Hannelore Glaubrecht, for her emotional participation in our Sulawesi research.

Description. Shell ( Fig. 6 View FIGURE 6. T A,B): Small, dark brown, elongate conic, spire angle 11–17 °. Top whorls in adult specimens always corroded to a varying degree, 3–5 remaining whorls, can reach up to 13.9 mm ( Tab. 2 View TABLE 2 ). Axial and spiral ribs form reticulated pattern. Aperture oval, pointed at top and slightly siphonated at base. Columella and interior dark brown.

External morphology: Headfoot black, mantle edge serrated to a varying degree.

Operculum ( Fig. 6 View FIGURE 6. T C): ovate, last whorl strongly inflated, multispiral with 10 whorls.

Radula ( Fig. 6 View FIGURE 6. T D,E): 28–44 rows, 2.1–3.2 mm long, on average 13.7 teeth per mm (n= 5). Central tooth with very large and elongate squarish major denticle and one minor denticle on each side. Glabella narrow, with convex base. Lateral teeth with very much enlarged squarish major denticles and one minor denticle on each side. Marginal teeth shovel-like, inner and outer marginals with three denticles each, the outermost ones considerably wider than the inner ones.

Reproductive biology: Brood pouch contains 1–2 embryos, their size can reach 3.1 mm (Tab. 3).

Embryonic shells ( Fig. 6 View FIGURE 6. T F–H): Ovate-conic, with strong axial ribs emerging on the 2 nd to 3 rd whorl and fading on the 5 th whorl. Shallow, widely spaced spiral ribs emerge on 3 rd to 4 th whorl (Tab. 3).

Distribution and habitat. South Sulawesi, Lake Mahalona, cape on NW shore ( Fig. 1 View FIGURE 1 B).

This species was collected on rocks in shallow water (less than 0.5 m depth).

Taxonomic remarks. T. hannelorae   is the smallest species within the Malili lakes species flock. Its size in combination with the reticulate shell sculpture generally can serve to distinguish it unambiguously from all other species in the system. While T. hannelorae   might be mistaken for subadult specimens of T. confusa Rintelen, Bouchet & Glaubrecht, 2007   , at first glance, the shell corrosion of the upper whorls characteristic for older animals will allow identifying any specimen as a fully grown adult.

Molecular phylogeny. The topology of the 16 S ML phylogram based on 851 bp of mitochondrial 16 S rDNA ( Fig. 7 View FIGURE 7 ) is basically identical to the tree presented in Rintelen et al. (2004) except for the inclusion of two of the new species described here, T. baskasti   and T. sinabartfeldi   (all attempts to sequence T. hannelorae   failed). Both species belong to a clade of smooth-shelled or spirally-ribbed taxa (clade Malili 2, compare Rintelen et al. 2004, 2007), where they form a poorly supported subclade which is sistergroup to all remaining species of clade Malili 2 but for one individual of T. sarasinorum ( Kruimel, 1913)   from the outlet bay of Lake Towuti clustering with T. baskasti   and T. sinabartfeldi   . While the three haplotypes of T. sinabartfeldi   are identical, T. baskasti   appears paraphyletic with an intraspecific sequence divergence of 0.6 % (p-distance).

MZB

Museum Zoologicum Bogoriense

ZMB

Museum für Naturkunde Berlin (Zoological Collections)