Pseudamnicola (Corrosella) iruritai, Delicado & Machordom & Ramos, 2011

Delicado, Diana, Machordom, Annie & Ramos, Marian A., 2011, Underestimated diversity of hydrobiid snails. The case of Pseudamnicola (Corrosella) (Mollusca: Caenogastropoda: Hydrobiidae), Journal of Natural History (J. Nat. Hist.) 46 (1 - 2), pp. 25-89 : 61-70

publication ID	https://doi.org/ 10.1080/00222933.2011.623358
persistent identifier	https://treatment.plazi.org/id/03C9996E-FFE3-2C19-EBCD-8D92FD4AFDC6
treatment provided by	Felipe
scientific name	Pseudamnicola (Corrosella) iruritai
status	sp. nov.

Treatment

Pseudamnicola (Corrosella) iruritai View in CoL sp. nov

Type locality

Don Pedro spring at Loja, Granada, Spain, UTM: 30S 0399460/4115074.

Type material

We have selected as holotype, one shell that, although eroded, represents the most frequent shape of the shells of P. (C.) iruritai . As a result of extensive erosion of this species’ shells, paratypes are very important to provide a reference model of the species. Therefore, the type material consists of: holotype MNCN 15.05 View Materials /53708a ( ESEM preparation, Figure 18B View Figure 18 ). Paratypes of around 80 specimens collected at different times: JM.B., MNCN 15.05 View Materials /53708b (96% ethanol) and MNCN / ADN 34967–34969 View Materials (96% ethanol); JM.B., MNCN 15.05 View Materials /53709 (96% ethanol); D.D. and C.N., 20 April 2009, MNCN 15.05 View Materials /53710 (70% ethanol, absolute ethanol and ESEM preparation, Figures 18 View Figure 18 , 19 View Figure 19 ) and MNCN / ADN 34970–34974 View Materials (absolute ethanol); I.B., 16 February 2010, MNCN 15.05 View Materials /53711 (70% ethanol) and MNCN / ADN 34975–34976 View Materials , 39780 View Materials (absolute ethanol) .

Other populations examined

This species has been found at only one further locality near the type locality: ditch of Don Pedro spring, Loja, Granada, UTM: 30S 0399460/4115074, D.D. and C.N., 19 April 2009, MNCN 15.05 View Materials /53712 (70% ethanol) and MNCN / ADN 34947–34951 View Materials (96% ethanol) .

Etymology

Dedicated to José María Irurita, Head of the Flora and Fauna Department (Delegación Provincial de Granada, Consejería de Medio Ambiente, Junta de Andalucía) for his contribution to the knowledge of freshwater hydrobiid fauna and invertebrate conservation in Andalusia.

Diagnosis

Shell slender, inner lip rather thicker than outer; body whorl surface striated; pigmented intestine; female genitalia with a pyriform non-folded bursa copulatrix and a globular seminal receptacle with short duct; penis tapered with a small patch of black pigment in distal region, folded in the middle area; nervous system brown pigmented with a supraoesophageal connective around three times longer than suboesophageal.

Description

Shell yellowish periostracum with 4.5–5.5 spire whorls, height 4.20– 3.30 mm ( Figure 18A–C View Figure 18 , Appendix Table 1); body whorl occupies half of shell length, surface striped; teleoconch and protoconch usually very eroded, being difficult to assess the number of spire whorls; protoconch around 310 µm wide and nucleus width 140 µm ( Figure 18E,F View Figure 18 ); protoconch microsculpture non-appreciable even in juveniles because of surface grooves and folds due to erosion ( Figure 18G View Figure 18 ); peristome frontal, oval, complete, with thin outer lip and thicker inner lip in contact with body whorl hiding umbilicus; outer peristome simple, straight and very fragile ( Figure 18D View Figure 18 ).

Operculum with around 3.5 spire whorls ( Figure 19B View Figure 19 , Appendix Table 2); internal side has a convex edge and oval muscular attachment is near nucleus ( Figure 19A View Figure 19 ).

Radula medium size (22% total shell length) and approximately seven times longer than wide ( Figure 19C View Figure 19 , Appendix Table 4); around 50 rows of teeth; trapezoidal central tooth with a tongue-shaped central cusp and six laterals of decreasing size, pointed tips ( Figure 19D,E View Figure 19 ); lateral teeth of left column with four tapered lateral cusps next to central one and three lateral cusps in right column in the three radulae analysed; inner marginal tooth has approximately 20 pointed cusps and outer marginal tooth around 25 shorter cusps ( Figure 19D,F View Figure 19 ).

Pigmentation and anatomy. Head and dorsal side of tentacles dark brown pigmented ( Figure 20D View Figure 20 ); ocular region not pigmented; dorsal region of foot also pigmented; pigment on neck clearer than on head; snout as long as wide and tentacles longer than snout; foot of intermediate size. Ctenidium with around 18 well-developed gill filaments occupying most of pallial cavity; osphradium appears in opposite middle of the ctenidium and is two times longer than wide ( Figure 20C View Figure 20 , Appendix Table 3). Stomach with a posterior chamber larger than anterior, caecum relatively long (Appendix Table 5); style sac shorter than stomach projected under intestine in some specimens; intestine has clear brown pigment ( Figure 20F View Figure 20 ); rectum slightly S-shaped in pallial cavity.

Female genitalia contains an albumen gland smaller than capsule gland with two regions (anterior region is more whitish) ( Figure 20G View Figure 20 ); bursa copulatrix pyriform nonfolded with straight bursal duct shorter than bursa length ( Figure 20H View Figure 20 , Appendix Table 6); pyriform seminal receptacle attached close to base of renal oviduct; straight renal oviduct with pale brown pigmentation from the point where it joins with the bursal duct; darker further along making one or two folds.

Male genitalia with a prostate gland three times longer than wide (Appendix Table 7); vas efferens entering the medial-posterior region and pallial vas deferens emerging from the anterior region ( Figure 20E View Figure 20 ); penis pointed with a wide base, some folds in the middle section and a small expansion near the tip where it contains a patch of clear brown pigment; it is attached to the central region of head ( Figure 20D View Figure 20 ); penial duct runs straight along the right side of penis.

Nervous system brown pigmented, darker on ganglia than on connectives and commissures; cerebroidal ganglia equal in size as well as pleural ganglia; supraoesophageal connective more than three times longer than suboesophageal ( Figure 20B View Figure 20 , Appendix Table 8); RPG ratio 0.44 (moderately concentrated); straight oesophagus running beneath nervous system ( Figure 20A View Figure 20 ).

Remarks

This species was only found at two very close sites in the Granada province, intra- and inter-population variability being scarce. More variable quantitative characters are: width of penis base, length of bursa copulatrix and seminal receptacle, and length of nervous connectives and commissures. Another variable character is the position of the intestine with respect to the style sac, which either surrounds the sac or crosses it. This character varies among specimens even within populations.

Pseudamnicola (C.) iruritai sp. nov. is the only species of the Corrosella subgenus with an extensively eroded shell surface, a pyriform bursa copulatrix and asymmetry in radular columns of lateral teeth (four lateral cusps on left column and three on right column in the three radulae studied). Despite erosion, discriminant function analysis indicates scarce variation in shell shape ( Figure 25 View Figure 25 ) and the species, according to shell morphometry, is well differentiated from the rest of the species examined here.

In addition to a different shape of the bursa copulatrix, the seminal receptacle is globose and larger than in the rest of the species, especially compared with P. (C.) falkneri and P. (C.) bareai sp. nov., whose seminal receptacles are half the size of those in P. (C.) iruritai sp. nov. The penis is pointed as in P. (C.) manueli sp. nov., but wider, longer and the distal pigment patch is rounder and paler in P. (C.) iruritai sp. nov. This species also shows slight pigmentation at the base of the penis.

Pseudamnicola (C.) iruritai sp. nov. belongs to the same clade as P. (C.) luisi , P. (C.) marisolae sp. nov. and P. (C.) andalusica sp. nov. ( Figure 26 View Figure 26 ), showing similar shell and penis morphology. However P. (C.) iruritai sp. nov. differs from these according to the following features: (1) the size of specimens, being the smallest in the clade; (2) six lateral cusps on the central radular tooth in P. (C.) iruritai sp. nov., whereas in P. (C.) marisolae sp. nov. and P. (C.) andalusica sp. nov., the number of cusps is four and in P. (C.) luisi it is three; (3) 20 cusps on inner marginal radular teeth (11, 12 and 13 in P. (C.) marisolae sp. nov., P. (C.) luisi and P. (C.) andalusica sp. nov., respectively); (4) bursal duct much shorter than in the other three species (Appendix Table 6); (5) the bursa copulatrix non-folded yet folded in the others; (6) the seminal receptacle in P. (C.) iruritai sp. nov. is globular yet elongated in the rest.

Pseudamnicola (Corrosella) andalusica sp. nov.

Type locality

La Salud spring in Albanchez de Mágina, Jaén, Spain, UTM: 30S 0459004/4181366.

Type material

Holotype MNCN 15.05 View Materials /53713a ( ESEM preparation, Figure 21A View Figure 21 ), paratypes MNCN 15.05 View Materials /53713b (96% ethanol, Figure 21C–G View Figure 21 , 22 View Figure 22 ) and MNCN / ADN 39781–39787 View Materials (96% ethanol), JM.B. and I.B., 10 May 2009; I.B., 16 February 2010, MNCN 15.05 View Materials /53714 (70% ethanol, Figure 23 View Figure 23 ).

Other populations examined

This species was found at other sites in Málaga and Córdoba provinces: Eduardo spring, Alcaucín, Málaga, UTM: 30 S 04008 View Materials /4085, JM.B., 3 December 2008, MNCN 15.05 View Materials /49425 (96% ethanol, ESEM preparation, Figure 21B View Figure 21 ) and MNCN / ADN 39788–39793 View Materials (96% ethanol); Turvilla river, Canillas de Albaida , Málaga, UTM: 30S 0414592/4080904, JM.B., 5 December 2008, MNCN 15.05 View Materials /49426 (96% ethanol); El Piojo spring, Almedinilla, Córdoba, UTM: 30S 0404049/4143497, JM.B., 5 January 2009, MNCN 15.05 View Materials /49427 (96% ethanol); Morellana spring, Luque, Córdoba, UTM: 30S 0390679/4154251, JM.B., 2 January 2009, MNCN 15.05 View Materials /49428 (96% ethanol); Pilar spring, Cabra, Córdoba, UTM: 30S 0379367/4151133, JM.B., 14 January 2009, MNCN 15.05 View Materials /49429 (96% ethanol) .

Etymology

The name andalusica is a Latin adjective that refers to the Spanish southern region of Andalusia, where this species lives.

Diagnosis

Shell slender, peristome with inner lip thicker than outer; radula with four lateral cusps in central tooth and three in lateral tooth; intestine pigmented; female genitalia with a pyriform J-shaped bursa copulatrix and an elongated seminal receptacle with a short pigmented duct; renal oviduct brown pigmented; long penis with wide base, a large patch of black pigment on distal region and folds in the middle section; nervous system brown pigmented with dispersed pigment granules; supraoesophageal connective around four times longer than suboesophageal.

Description

Shell yellowish periostracum, with four to five spire whorls ( Figure 21A,B View Figure 21 , Appendix Table 1), height 3.60– 3.20 mm; protoconch approximately 475 µm wide, with 1.3 whorls and nucleus around 200 µm long ( Figure 21D,E View Figure 21 ); protoconch microsculpture slightly grooved ( Figure 21F View Figure 21 ); body whorl about two-thirds of total length; peristome frontal, complete, oval, with thin outer lip and thicker inner lip which partially hides the umbilicus; edge of peristome simple and straight ( Figure 21C View Figure 21 ).

Operculum with around three spire whorls ( Figure 22A,B View Figure 22 , Appendix Table 2) and oval muscle attachment on internal side near the nucleus.

Radula around 45 rows of teeth; intermediate length (23% total shell length) and around nine times longer than wide ( Figure 22C View Figure 22 , Appendix Table 4); trapezoidal central tooth with a long central cusp and four tapered lateral cusps, slightly sharpening towards central one ( Figure 22D,E View Figure 22 ); lateral teeth with three sharp lateral cusps, the last one very short; inner marginal teeth contain 13 sharp cusps, shortening towards the base of tooth; outer marginal teeth with around 15 tapered cusps ( Figure 22D,F View Figure 22 ).

Pigmentation and anatomy. Head dark brown pigmented from snout to neck ( Figure 23D View Figure 23 ); brown pigment also on tentacles but ocular lobes and tip nonpigmented; snout as long as wide, with medial lobation; foot of intermediate length, pigmented dorsal region. Ctenidium composed of around 20 well-developed gill filaments longer than wide situated in middle region of pallial cavity; ellipsoidal osphradium under central gill filaments ( Figure 23C View Figure 23 , Appendix Table 3). Stomach slightly longer than wide ( Figure 23E View Figure 23 ); long gastric caecum; style sac longer than wide, with clear brown pigment and surrounded by brown pigmented intestine (Appendix Table 5).

Female genitalia ( Figure 23G View Figure 23 , Appendix Table 6) with albumen gland smaller than capsule gland and transparent; capsule gland contains two regions, the anterior one being more transparent; bursa copulatrix pyriform J-shaped with a duct slightly shorter than bursa length; elongated seminal receptacle with short brown pigmented duct ( Figure 23H View Figure 23 ) linked to renal oviduct above the insertion of bursal duct; renal oviduct straight with clear brown pigment from the joining point of bursal duct to the oviduct fold, from which the oviduct is dark brown pigmented and makes two or three loops thereafter.

Male genitalia with a prostate gland around three times longer than wide (Appendix Table 7), vas efferens enters the medial region and vas deferens emerges at its anterior edge ( Figure 23E View Figure 23 ); penis long, slender, with a blunt distal end and a large grey patch of pigmentation in its middle-distal region; attached to the central head area with some folds in its middle region ( Figure 23D View Figure 23 ); penial duct running straight close to the external side of penis.

Nervous system brown pigmented, darker on ganglia than connectives and commissures, with dispersed pigment granules; cerebral ganglia and pleural ganglia approximately equal in size; supraoesophageal ganglion slightly longer than suboesophageal, and supraoesophageal connective approximately four times longer than suboesophageal ( Figure 23A,B View Figure 23 , Appendix Table 8). RPG ratio 0.43 on average (moderately concentrated).

Remarks

Morphological variability between the two populations examined is mostly found in the female genitalia. Females from Eduardo spring (Málaga) have a wider and shorter bursal duct than those from the type locality and a shorter seminal receptacle without pigment. However, preliminary molecular results indicate relatively low genetic divergence between them (1.8%). These characters are therefore insufficient to consider them different species.

Among the species belonging to the same clade, P. (C.) andalusica sp. nov. shares most synapomorphies with P. (C.) marisolae sp. nov., such as shell size and shape ( Figure 25 View Figure 25 ), a slender and pigmented seminal receptacle and a slender penis with a large patch of brown pigment. However, genetic divergence is clear (from 6.38 to 6.54%, Appendix Table 9) and anatomical differences exist to suggest this species as new. These differences are: (1) pallial oviduct shorter in P. (C.) andalusica sp. nov. than in P. (C.) luisi and P. (C.) marisolae sp. nov., (2) bursal duct with an expansion near the joining point with the renal oviduct in P. (C.) marisolae sp. nov. that is absent in P. (C.) andalusica sp. nov.; (3) wavy bursal duct in P. (C.) andalusica sp. nov. and straight in P. (C.) luisi , P. (C.) marisolae sp. nov. and P. (C.) iruritai sp. nov.; (4) longer penis in P. (C.) andalusica sp. nov. than in P. (C.) marisolae sp. nov. and P. (C.) iruritai sp. nov., and shorter than in P. (C.) luisi ; (5) lateral radular teeth formula 3-C- 3 in P. (C.) andalusica sp. nov., 2-C- 2 in P. (C.) luisi and P. (C.) marisolae sp. nov. and 3/4-C-3/ 4 in P. (C.) iruritai sp. nov.