Chondrobasis levantina Ramos and Arconada, 2001

Arconada, B. & Ramos, M. A., 2001, New data on Hydrobiidae systematics: two new genera from the Iberian Peninsula, Journal of Natural History 35 (7), pp. 949-984 : 970-976

Chondrobasis levantina Ramos and Arconada new species

(®gures 13A±H, 14A±F, 15A±F, 16A±D; tables 1±4)

Synonymy

HauOEenia (Neohoratia) sturmi (Rosenhauer) , Boeters, 1981: 55 ±56 (shell and anatomy). HauOEenia sturmi (Rosenhauer) , Bernasconi, 1986: 186 (in part).

Horatia (?) sturmi (Rosenhauer) , Boeters, 1988: 220 (shell and anatomy).

Material examined

HOLOTYPE. MNCN.1505 / 33262 (gold-coated SEM mount) (®gure 13A).

PARATYPES. This species has been found in ®ve provinces from the east of Spain: CastelloÂn (Ca), Valencia ( V), Alicante (A), Teruel ( T) and Cuenca (C) as follows: San Miguel spring, Viver, CastelloÂn, UTM: 30SVF493951 7 March 1990, R.A., D.M. and J.M. R., MNCN.15.05 / 33262 (ethyl alcohol material and gold-coated SEM mount), 29 September 1990, E. R., MNCN.15.05 / 33280 (ethyl alcohol material and gold-coated SEM mount), 7 June 1994, G. T., MNCN.15.05 / 33264 (ethyl alcohol material) 25 May 1998, B.A., MNCN.15.05 / 33285 (ethyl alcohol, frozen material and gold-coated SEM mount). MZUF: 17998 (two paratypes), MNHN (two paratypes), SMF: 312503 (two paraypes) and NNM: 59381 (two paratypes). Ragudo spring, Viver, Ca ( UTM: 30SYK03124 7) 7 June 1994, G. T., MNCN.15.05 / 33265 (ethyl alcohol material), 26 May 1998, B.A., MNCN.15.05 / 33286 (ethyl alcohol material, frozen material and gold-coated SEM mount); Los Nogales spring, Benafer, Ca ( Boeters, 1981: 56) ( UTM: 30SYK07123 5) 29 September 1990, E. R., MNCN.15.05 / 33279 (ethyl alcohol material), 7 June 1994, G. T, MNCN.15.05 / 33267 (ethyl alcohol material), 26 May 1998, B.A., MNCN.15.05 / 33288 (ethyl alcohol and frozen material); El Tober spring, Viver, Ca ( UTM: 30SYK042 3) 24 June 1994, G. T., MNCN.15.05 / 33275 (ethyl alcohol material); Ojos del Prado , Viver, Ca ( UTM: 30SYK0324) 26 May 1998, B.A., MNCN.15.05 / 33287 (ethyl alcohol and frozen material); Fuente Bella, Jarafuel, V ( UTM: 30SXJ6433) 13 June 1993, G. T., MNCN.15.05 / 33266 (ethyl alcohol material and gold-coated SEM mount); Las Aguas, Ayora, V ( UTM: 30SXJ67824 9) 20 May 1994, G. T., MNCN.15.05 / 33269 (ethyl alcohol material), 28 May 1998, B.A., MNCN.15.05 / 33292 (ethyl alcohol and frozen material); Las Ventanas, Chelva, V ( UTM: 30SXK710 1) 30 May 1992, G. T., MNCN.15.05 / 33272 (ethyl alcohol material); La Gitana spring, Chelva, V ( UTM: 30SXK700 3) 30 May 1992, G. T., MNCN.15.05 / 33276 (dried and ethyl alcohol material); Butaya spring, Cofrentes, V ( UTM: 30SXJ684 4) 13 June 1993, G. T., MNCN.15.05 / 33274 (ethyl alcohol material); Caroche spring, Teresa de Cofrentes , V ( UTM: 30SXJ79929 5) 20 May 1994, G. T., MNCN.15.05 / 33278 (ethyl alcohol material and gold-coated SEM mount), 28 May 1998, B.A., MNCN.15.05 / 33291 (ethyl alcohol and frozen material); La Pica spring, VinÄuelas, V ( UTM: 30SXJ715 5) 5 May 1994, E. R., MNCN.15.05 / 33281 (ethyl alcohol material); Micarient spring, Montixelvo, V ( UTM: 30SYJ310 7) 7 April 1994, G. T., MNCN.15.05 / 33277 (ethyl alcohol material); La Mina spring, Jarafuel, V ( UTM: 30SXJ64534 1) 28 May 1998, B.A., MNCN.15.05 / 33290 (ethyl alcohol and frozen material); Mijares river , Yatova, V ( UTM: 30SXY785 9) 18 February 1990, G. T., MNCN.15.05 / 33271 (ethyl alcohol material); Amadoiro river (lotic), Relleu, Alicante ( UTM: 30SYH3275) 1 April 1990, G. T., MNCN.15.05 / 33270 (ethyl alcohol material); Amadoiro river (lentic), Relleu, Alicante ( UTM: 30SYH327 5) 1 April 1990, G. T., MNCN.15.05 / 33273 (ethyl alcohol material); spring in Arcos river , Arcos Salinas, T ( UTM: 30TXK6226) 28 August 1993, G. T., MNCN.15.05 / 33268 (ethyl alcohol material and gold-coated SEM mount); spring between Priego and Poyatos, Mountains of Cuenca, C ( UTM: 30TWK7676) 1 October 1992, E. R., MNCN.15.05 / 33282 (dried and ethyl alcohol material); spring near Escabas river , El Hosquillo ( UTM: 30TWK85771 8) 2 September 1992, E. R., MNCN.15.05 / 33283 (ethyl alcohol material); spring in Boniches, between CanÄete and Landete, C ( UTM: 30SXK17527 3) E. R., MNCN.15.05 / 33284 (ethyl alcohol material) .

Type locality. San Miguel spring, Viver, CastelloÂn, UTM: 30SVF493951.

Etymology. The name `levantina ’ derive from`Levante’ which refers to the geographical area comprising the East of the Iberian Peninsula, where the species is distributed.

Morphology

Shell (®gures 13A±H, 14A±C, table 1). Shell with 3.125±3.5 spire whorls. It is short and wide. The width of the protoconch is approximately 390 m m and it has a narrow nucleus that measures around 144 m m. The body whorl is very broad and occupies approximately six-sevenths of total shell length. The shell is yellowish and has, generally, whitish deposits.

Operculum (®gure 14D, E, table 2). Operculum colour can vary from pale yellowish (Viver type locality, VinÄuelas, Mijares), to light yellowish (Cuenca populations, Fuente Ragudo, Viver) and bright orange (Teresa de Cofrentes, Ayora, Benafer, etc.).

External body features (®gure 16A). The snout is darkly pigmented, but the rest of the head is grey. The central part corresponding to the buccal mass is less pigmented. On the contrary, the mantle epithelium is intensely black pigmented. The cephalic tentacles show a black median longitudinal streak and a totally unpigmented tip. In live specimens it is possible to distinguish some white iridescent granules around the eyes.

Nervous system. The ganglia have black pigment on their outer surface. The RPG ratio is 0.34.

Radula (®gure 15A±F, table 3). Radular ribbon narrow, measuring more than 557.5 m m approximately, with approximately 67 rows of teeth. The central cusp of the central tooth is long, tapered and ¯anked by four to seven small but well-de®ned lateral denticles on each side. This cusp clearly protrudes from the lateral denticles. The upper border of the central tooth is weakly excavated. The distance between the basal cusps of the central teeth is approximately 7 m m. Lateral teeth with a central cusp ¯anked by four to six inner cusps on the left side and by four to seven on the right side. Inner marginal teeth with 29±32 very regular cusps. In all the radulae studied these cusps were fused in groups, mainly in its basis.

Female reproductive system (®gure 16C, D, table 4). The pallial oviduct constitutes more than one-third of the pallial cavity. The capsule gland occupies more than half the pallial oviduct but, in some cases, we saw females with a very poorly developed capsule. The bursa copulatrix is pyriform-elongated, well developed and constitutes more than one-third of the length of the pallial oviduct. Its duct is very short or virtually non-existent. Exceptionally, in some females, the RS2 is very small and is seen as a protuberance on the renal oviduct.

Male reproductiv e system (®gures 14F, 16A, B, table 4). The penis is long (slightly longer than the head), needle-shaped, narrow and unpigmented. Its base is small and ends in a small papilla, sometimes very slightly developed. This papilla, when the penis is contracted, points to the mantle cavity. Our histological studies did not reveal any glandular tissues in this lobe. The penial duct strongly undulates in the penis basis. Almost half of the prostate is located inside the pallial cavity.

Remarks. Although a high degree of resemblance seems to link these species, there are some relevant diOEerences between Ch. levantina and B. sturmi and B. davisi , which justify their separation in two diOEerent genera. Chondrobasis levantina has a more developed wrinkled protoconch microsculpture. Its shell shape is shorter and wider and the aperture is lower. Head pigmentation is lighter than in B. sturmi but more similar to that of B. davisi . The radula is narrower than in B. sturmi but wider than in B. davisi , the central denticle of the central teeth is longer and more tapered compared to that of both latter species. The upper border of the cutting edge is less excavated in Ch. levantina , being markedly U-shaped in the other two species. There are more inner marginal teeth cusps and they are often attached in pairs. As regards the male genital system, the penis base of Ch. levantina is longer and more slender and ends in a small papilla. In this species, the penial duct strongly undulates at the penis basis. The renal oviduct coils in a simple 360ss loop in B. sturmi and B. davisi while it is usually S-shaped in Ch. levantina . The RS2 is tightly pressed to the renal oviduct in Ch. levantina while in B. sturmi and B. davisi it leans over the bursa copulatrix. The bursa copulatrix is longer and pyriform in Ch. levantina instead of roundish as in B. sturmi , and its duct is also shorter or almost non-existent compared to Boetersiella species.

In the study populations, the presence of a small RS2 was related to a simple loop in the oviduct instead of an S-shaped twist as occurs in populations with a well-developed RS2. However, the shape of the RS may vary within a species depending on the amount of sperm it contains ( Hershler and Ponder, 1998). This suggests that the intraspeci®c diOEerences described in Ch. levantina could be attributed to physiological diOEerences among populations. In fact, the rest of the anatomical features are identical in all the specimens.

Habitat and distribution. This widely distributed species has been found in springs, irrigation ditches and living over the stones, sand, leaves and aquatic vegetation in the provinces of CastelloÂn, Valencia, Alicante, Teruel and Cuenca. Other freshwater molluscs living in sympatry are: Ancylus sp. , Physa acuta (Draparnaud 1805) , Lymnaea peregra (MuÈller, 1774) , Lymnaea truncatula (MuÈller, 1774) , Succinea sp. , Theodoxus , sp., Melanopsis sp. , Belgrandia marginata (Michaud, 1831) , Bythinella batalleri Bo ®ll, 1925, Potamopyrgu s antipodarum (Gray, 1843), Pseudamnicola (Pseudamnicola) spirata (Paladilhe, 1869) , Neohoratia schuelei ( Boeters, 1981) , Pisidium casertanum (Poli, 1791) and Pisidium personatum Malm, 1855 .