Opacuincola lisannea Verhaegen & Haase 2021, sp. nov.
Creators: name: Verhaegen, Gerlien
name: Haase, Martin
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Littorinimorpha
Hydrobiidae
Opacuincola
Opacuincola lisannea

description: Opacuincola lisannea sp. nov.
urn:lsid:zoobank.org:act: FD252AD2-B0D4-4996-9F13-38F4002D5CA6
Figs 4 C–D, 5 B–C, 6 B–C, 8 B, 10, 11 A; Tables 1–2
Diagnosis
The new species is a slender-conical Opacuincola most similar to the smaller Op. terraelapsus. Opacuincola takakaensis is larger and more conical. Compared to Op. terraelapsus, the new species has a larger bursa copulatrix reaching much farther behind the albumen gland than in the latter, and the huge penis has no subterminal swelling and has a lobe that points forward rather than to the right. Compared to all other congeners, Op. lisannea sp. nov. had 20 diagnostic DNA positions.
Etymology
Opacuincola lisannea sp. nov. is dedicated to Lisanne Verhaegen, the sister of the first author, on the occasion of her 30 th birthday. She is in part responsible for the debut of the first author as a biologist by proofreading numerous of her applications, including the one for her PhD position, resulting in the discovery of this new species.
Material examined
Holotype (Fig. 4C) NEW ZEALAND • Kahurangi National Park, SW of Collingwood, Kaituna Track; 40°42ʹ36.3ʺ S, 172°33ʹ36.3ʺ E; 28 Feb. 2016; G. Verhaegen and M. Haase leg.; on leaves, stones, woody debris in small spring; NMNZ.M.330189.
Paratypes (Figs 4D, 5 B–C) NEW ZEALAND • 19 specs; same collection data as for holotype; NMNZ.M.330190 • 14; Kahurangi National Park, SW of Collingwood, Kaituna Track; 40°42ʹ30.5ʺ S, 172°33ʹ50.9ʺ E; 28 Feb. 2016; G. Verhaegen and M. Haase leg.; on leaves, stones, woody debris in small spring; NMNZ.M.330201.
Description
SHELL (Figs 4 C–D, 5 B–C). Slender-conical to pupiform, about 1.8 times as high as than wide, whitetranslucent with light brown periostracum; protoconch with fine pits comprising ca 0.85 whorls (Fig. 6 B– C); entire shell with 3.75 to 4.375 whorls, teleoconch with fine longitudinal ridges on first 0.25 whorl, then without structure apart from growth lines; umbilicus narrow; aperture orthocline, almost circular, only slightly higher than wide.
OPERCULUM. Light orange, paucispiral; nucleus submarginal, without peg.
EXTERNAL FEATURES. Epidermis without pigment; eyes small with bean-shaped pigment spot; tentacles without particular ciliation.
MANTLE CAVITY (n = 5). 9–12 ctenidial filaments; osphradium ovate-elongate, behind middle of gill. DIGESTIVE SYSTEM. Radula has formula R 4-6 1 4-6/3-4 3-4, L 5-6 1 5, M1 23-26, M2 26-33 (Fig. 8B); stomach without caecum; intestine makes loop in roof of mantle cavity, which is clearer in males than in females due to different sizes of pallial genital glands.
FEMALE GENITALIA (n = 2; Fig. 10A). Ovary short, simple sac starting 1.5 whorls below apex, comprising 0.25 whorl and not reaching stomach; renal oviduct first coiling 180° clockwise, then 270° counterclockwise; one distal, large receptaculum seminis lying ventrally against bursa copulatrix; bursa copulatrix large, ellipsoid, underneath and reaching far behind albumen gland, bursal duct entering anteriorly; ovoviviparous, brooding at least one embryo in pallial oviduct, pallial oviduct as brood pouch with short albumen gland as well as longer capsule gland, the latter histologically uniform in CT scans.
MALE GENITALIA (n = 5; Fig. 10B). Testis lobate sac, starting ca 0.75 whorl below apex, comprising ca 0.75 whorl, anteriorly just reaching stomach; vesicula seminalis coils along anterior half of testis; proximal vas deferens inserts close to middle of kidney-shaped prostate, distal vas deferens leaving anteriorly; penis large, continuously tapering, ending with broad, cylindrical filament, huge muscular lobe on right side pointing forward (Figs 10B, 11A).
Remarks
With respect to all other sequenced congeners, Op. lisannea sp. nov. had 14 diagnostic characters in COI and six in 16S, respectively (Table 2). In the phylogeny, it was a well-supported sister species to five other species of the genus (Fig. 2). Morphologically, the new species is most similar to Op. terraelapsus. The latter is smaller (shell height, ANOVA: df = 2, 50; F= 79.17; p <0.0001; Tukey’s pairwise posthoc tests: p <0.004 in all three cases), but the species cannot be distinguished in shape (shell height/ shell width, Kruskal-Wallis test: H = 4.409; p = 0.110; pairwise Mann-Whitney U-tests: p> 0.05 in all three cases). This is perfectly reflected in the PCA, where the species largely overlap only along PC2 (Fig. 3). In February 2016, we again failed to find Op. terraelapsus. It was originally collected in a trickle somewhere at the start of the Fenian track near Karamea in 1976, blocked by a landslide in 2002 when MH first attempted to relocate this species (see Haase 2008). Whether Op. terraelapsus has survived until today can only be hoped. The reduced eyes suggest that Op. lisannea sp. nov. dwells in the transition zone of epigean and ground waters. At the type locality of the new species, we also collected Catapyrgus jami sp. nov.
description: Published as part of Verhaegen, Gerlien & Haase, Martin, 2021, All-inclusive descriptions of new freshwater snail taxa of the hyperdiverse family Tateidae (Gastropoda, Caenogastropoda) from the South Island of New Zealand, pp. 71-96 in European Journal of Taxonomy 731 on pages 82-84, DOI: 10.5852/ejt.2021.731.1205, http://zenodo.org/record/4446916