Iglicopsis butoti Falniowski & Hofman, 2021

Falniowski, Andrzej, Lewarne, Brian, Rysiewska, Aleksandra, Osikowski, Artur & Hofman, Sebastian, 2021, Crenobiont, stygophile and stygobiont molluscs in the hydrographic area of the Trebisnjica River Basin, ZooKeys 1047, pp. 61-89 : 61

Iglicopsis butoti Falniowski & Hofman sp. nov.

Fig. 9M-P

GenBank no.

COI: MW879273-MW879275; H3: MW865749-MW865751

Type materials.

Holotype. Ethanol-fixed specimen (Fig. 9M ), Vrelo „Polički Studenac" (Crkvina); a cave spring in the left bank of and adjacent to the Trebišnjica River (N 42.71288, E 18.36514) (our locality 13, Fig. 4 ) close to Trebinje (Bosnia and Herzegovina), interstitially, 50 cm below the gravel floor of the spring; in the collection of the Department of Malacology of Jagiellonian University, voucher number ZMUJ-M.2651.

Paratypes. Three paratypes destroyed to extract DNA, one specimen ethanol-fixed, in the collection of the Department of Malacology of Jagiellonian University, ZMUJ-M.2652.

Diagnosis.

Shell minute, ovate-conic, distinguishable from Montenegrospeum by a more oval habitus, broader spire and broader flat apex, sometimes showing scalarity at the body whorl; the penis with the left-side outgrowth located more proximally and bi-lobed, and additional flat outgrowth on the right side.

Description.

Shell (Fig. 9M-P ) up to 1.49 mm high and 0.55 mm broad, ovate-conic, whitish, translucent, thin-walled, and consisting of about five whorls, growing regularly and separated by moderately deep suture. Spire high and broad, apex broad and flat, body whorl less than 0.5 of the shell height, Aperture small, prosocline, oval in shape, peristome complete and thin, somewhat swollen, in contact with the wall of the body whorl, in some specimens showing scalarity close to the aperture, umbilicus slit-like. Shell surface smooth, with growth lines hardly visible.

Measurements of holotype and sequenced and illustrated shells: Table 3 . Shell variability slight; scalarity and much bigger dimensions of one specimen (Fig. 9P ) most probably caused by the larval Trematoda (parasite gigantism).

Soft parts morphology and anatomy. Body white, pigmentless, with no eyes. Ctenidium with nine short lamellae, osphradium elongated. Tectum forming a characteristic broad loop (Fig. 9N ). Female reproductive organs with unpigmented renal oviduct, bursa copulatrix and two small receptacula seminis; details unknown.

The radula (Fig. 12 ) with the central tooth cusp formula:

(4)3-1-3(4)1-1 or (5)4-1-4(5)1-1

Rather long and slender cusps grow regularly to central one. Lateral cusp with 5 - 1 - 5(6) long and massive cusps. Inner marginal tooth with ca 23 slender cusps of nearly invariable length along the tooth edge, outer marginal tooth with 26 broadly triangular cusps.

Penis (Fig. 13A ) long, tapering, below the half of its length, proximally, bi-lobed outgrowth on the left side and flat outgrowth at the right side, at the distal part and the vas deferens well visible inside, running in zigzags.

Derivatio nominis.

The genus name refers to the similarity of the shell to the moitessieriid genus Iglica Wagner, 1927. The specific epithet Iglicopsis butoti refers to the memory of Dr Louis J. M. Butot, a Dutch malacologist devoted mostly to the Greek malacofauna, good friend and the mentor of AF.

Distribution and habitat.

Known from the type locality only.

Molecular relationships.

despite its shell morphology, Iglicopsis clearly belongs to the Hydrobiidae Stimpson, 1865, Sadlerianinae Szarowska, 2006, and not to the Moitessieriidae Bourguignat, 1863 (Fig. 8 ). Its sister species is Montenegrospeum bogici in the H3 tree (Fig. 8 , bootstrap 95%), and on the tree based on both concatenated loci (but with bootstrap 63% only); in the COI tree the bootstrap does not support its phylogenetic position.

Figures

Figure 4. Distribution of the studied taxa. Localities' numbers correspond to Table 1.

Figure 8. Phylogenetic relationships of Travunijana and Iglicopsis based on COI, H 3 and concatenated loci; bootstrap supports given if over 60 %, their values together with Bayesian probabilities.

Figure 9. Shells: A-L Travunijana vruljakensis M-P Iglicopsis butoti M holotype N 2 F 61 O 2 F 68 P 2 F 69 (extraction numbers, see Table 3). Scale bars: 1 mm.

Figure 12. Radula of Iglicopsis butoti, scale bars: 10 µm.

Figure 13. A Penis of Iglicopsis butoti, scale bar: 0.1 mm B shell measurements: a - shell height, b - body whorl breadth, c - aperture height, d - spire height, e - aperture breadth, α - apex angle, β - angle between body whorl suture and horizontal surface.