Pseudamnicola reticulatus Delicado, Boulaassafer & Hauffe, 2025

Pseudamnicola reticulatus Delicado, Boulaassafer & Hauffe sp. nov.

( Figs 13 View Figure 13 , 14 View Figure 14 )

Pseudamnicola orsinii (Küster, 1852) — Delicado et al. 2015

Pseudamnicola sp. 5 — Delicado et al. 2018

Pseudamnicola sp. 5 — Boulaassafer et al. 2020

ZooBank registration: urn:lsid:zoobank.org:act:CD01E3A2-61DA-4003-8950-F6743F7FCB01

Etymology

In Latin, reticulatus means reticulated, describing the net-like shell sculptures found in the type population.

Type material

Holotype ( MNCN 15.05 About MNCN /200503H; dissected animal) and one paratype ( MNCN 15.05 About MNCN /200503P) in the MNCN collection and six paratypes in the UGSB collection ( UGSB 5971 ). Type locality: a spring discharging to the Fiumefreddo River , Fiumefreddo di Sicilia, Sicily, Italy.

Material studied

A spring discharging to the Fiumefreddo River , Fiumefreddo Sicilia, Sicily, Italy, 37.7851°N, 15.2271°E, leg. M.B., January 2008, MNCN 15.05 About MNCN /200503 and UGSB 5971 (80% ethanol) GoogleMaps .

Diagnosis

Shell small, ovate-conic, with a fine net-like surface sculpture (in the type population); protoconch microsculpture pitted; central radular tooth formula (4)3-C-3(4)/1-1; bursa copulatrix medium-sized, pyriform, with a duct longer than bursal length; SR1 long, elongate, with a short duct; penis gradually tapering, with many folds over the entire surface, a moderately wide base, and a small patch of pigmentation on its distal region; nervous system darkly pigmented, elongate (mean RPG ratio =.52).

Description

Shell ovate-conic, whorls 3.5–4, height 2.00– 3.25 mm, with a fine net-like surface sculpture (in the type population) ( Fig. 13A–C View Figure 13 ; Supporting Information, Table S3). Periostracum yellowish to whitish. Protoconch ~500 µm wide, eroded in the type population, whorls 1.5; nucleus ~150 µm wide; protoconch microsculpture pitted ( Fig.13G View Figure 13 ). Teleoconch whorls moderately convex, with deep sutures; body whorl large, occupying about three-quarters of total shell length. Aperture longer than wide, slightly oval; inner lip thicker than outer lip; peristome margin simple, straight ( Fig. 13D View Figure 13 ). Umbilicus narrow, not covered by the inner lip. Holotype: SL = 3.28 mm, SW = 2.23 mm, AL = 1.85 mm, and AW = 1.40 mm.

Operculum oval, yellowish, about two and a half whorls; muscle attachment area oval and located near the nucleus ( Fig. 13E, F View Figure 13 ).

Radular length intermediate, ~600 µm (~25% of total shell length), with ~55 rows of teeth ( Fig. 13H View Figure 13 ). Central tooth formula (4)3-C-3(4)/1-1 ( Fig. 13I View Figure 13 ); basal tongue V-shaped, length about equal to lateral margin. Lateral tooth formula 3-C-3. Inner marginal teeth having 15–20 tapered cusps, shortening towards the base. Outer marginal teeth with ~20 sharp cusps ( Fig. 13J View Figure 13 ).

Animal darkly pigmented, with pigmentation lighter on neck and tentacles ( Fig. 14F View Figure 14 ). Snout as long as wide, with medium distal lobation; foot size intermediate, with dorsal pigmentation. Ctenidium with ~20 well-developed gill filaments, occupying ~50% of pallial cavity length and posteriorly positioned. Osphradium of intermediate width and opposite middle of ctenidium ( Fig. 14A View Figure 14 ). Stomach slightly longer than wide, with two chambers almost equal in size and a medium-sized posterior caecum; style sac longer than wide, surrounded by an unpigmented intestine ( Fig. 14B View Figure 14 ; Supporting Information, Table S4). Nervous system elongate (mean RPG ratio =.52), darkly pigmented, darker on ganglia than on connectives and commissures; cerebral ganglia approximately equal in size ( Fig. 14C View Figure 14 ).

Female glandular oviduct approximately three times as long as wide. Albumen gland shorter than capsule gland. Bursa copulatrix small, pyriform, longer than wide. Bursal duct slightly longer than bursal length. Renal oviduct black-pigmented until the area above the insertion of seminal receptacle, relatively straight. Seminal receptacle elongate, with a short duct, joining renal oviduct at the insertion point with bursal duct ( Fig. 14D, E View Figure 14 ; Supporting Information, Table S5).

Male genitalia with a prostate gland approximately twice longer than wide, bean-shaped; seminal duct entering the middle-posterior region; pallial vas deferens emerging close to its anterior edge ( Fig. 14H View Figure 14 ). Penis as long as head, gradually tapering, with many folds over the entire surface and a small patch of pigmentation on its distal region ( Fig. 14F, G View Figure 14 ; Supporting Information, Table S6); base moderately wide; attached well behind the right eye; penial duct narrow, curved, coursing close to outer edge.

Habitat

Endemic to a small coastal spring.

Remarks

We dissected six of the eight specimens of P. reticulatus deposited in the UGSB collection and found only one female. All specimens had an eroded shell apex and a fine net-like shell sculpture, the latter feature atypical in Pseudamnicola . Delicado et al. (2015) identified the Pseudamnicola population occurring in the same spring near Fiumefreddo di Sicilia as P. orsinii . There is, however, a large genetic divergence (4% for COI) between the P. reticulatus and the newly sequenced snail from the type locality region of P. orsinii , in addition to morphological differences detected in shells and other anatomical structures, which might disprove this identification. The phylogenetic studies of Delicado et al. (2018) and Boulaassafer et al. (2020) inferred that the P. reticulatus clade was phylogenetically distant from the P. moussonii clade. The two species differ according to a set of morphological characters: the shell spire and aperture are wider in P. reticulatus (for comparison, see Giusti 1976; Falkner and Boeters 2003); the bursal duct and seminal receptacle of the single dissected female from the type locality of P. moussonii are slightly longer than the ones measured in the P. reticulatus female, but this difference needs confirmation; and the penis is generally wider in P. reticulatus .