Iberhoratia morenoi, Arconada & Delicado & Ramos, 2007

Arconada, Beatriz, Delicado, Diana & Ramos, M. Ángeles, 2007, A new genus and two new species of Hydrobiidae (Mollusca, Caenogastropoda) from the Iberian Peninsula, Journal of Natural History 41 (29 - 32), pp. 2007-2035 : 2011-2015

Iberhoratia morenoi new species

(Figures 2–4)

Type locality

Spring in Prado del Rey, Cádiz, UTM: 30STF8160 .

Material examined

Type material. Holotype: MNCN 15.05 /46980 ( SEM preparation, Figure 2A) . Paratypes: MNCN 15.05 /46980 ( SEM preparation, ethyl alcohol and frozen material).

Other populations examined. This species was found in the provinces of Cádiz , Sevilla , and Málaga ( Figure 1 ). Populations in Almería and Huelva have tentatively been assigned to this species as Iberhoratia cf. morenoi until new specimens are studied. Localities are the following: spring in Prado del Rey, Cádiz (type locality), UTM: 30STF8160, E. R., MNCN 15.05 /46980 (ethyl alcohol, SEM preparation); B. A., 16 April 1998, MNCN 15.05 /46981 (ethyl alcohol, SEM preparation, frozen material); Benamahoma, Cádiz, UTM: TF87 , 18 October 1998, E. R., MNCN 15.05 /46982 (ethyl alcohol); spring Los Palominos, Zahara, Cádiz, UTM: TF87 , 18 April 1998, E. R., MNCN 15.05 /46983 (ethyl alcohol); spring El Cañajoso, Coripe, Sevilla, UTM: 30STF848928, 24 April 1992, D. M., MNCN 15.05 /46984 (dried material); 16 April 1998, B. A., MNCN 15.05 /46985 (ethyl alcohol, SEM preparation); Casarabonela, Málaga, UTM: 30 SUF3572 , E. R., MNCN 15.05 /46986 (ethyl alcohol, SEM preparation); spring Matiaña, El Chorro, Málaga, UTM: 30 SUF4386 , 14 April 1998, B. A., MNCN 15.05 /46520 (ethyl alcohol, frozen material, SEM preparation); spring La Quemona, Málaga, UTM: 30 SUF0581 , E. R., MNCN 15.05 /46987 (ethyl alcohol), 15 April 1998, B. A., MNCN 15.05 /46988 (ethyl alcohol, frozen material); spring El Valentín, Alozaina, Málaga, UTM: 30 SUF3366 , 14 April 1998, B. A., MNCN 15.05 /46989 (ethyl alcohol) .

Iberhoratia cf. morenoi : spring in Bérchul , Félix , Gador mountains , Almería, UTM: 30SWF298813, E. R., MNCN 15.05 /46503 (ethyl alcohol and SEM preparation); 26 March 1998, B. A., MNCN 15.05 /46504 (ethyl alcohol, frozen material, SEM preparation); El Marchal de Antón López, Almería, UTM: 30SWF3383, 11 October 1992, E. R., D. M.; 26 March 1998, B. A., MNCN 15.05 /46502 (ethyl alcohol, frozen material); spring las Mimbreras, Zufre, Huelva, UTM: QB39, 2 August 2002, B. A., M. O., MNCN 15.05 /46990 (frozen material).

Material examined for morphometry. Shell measurements (Table I) correspond to the following populations: Ib. morenoi from Prado del Rey (type locality) and Ib. cf. morenoi from Félix. Operculum measurements (Table II) to: Ib. morenoi from Prado del Rey (type locality) and Ib. cf. morenoi from Félix and El Marchal de Antón López. Anatomical measurements (Tables III, V – VII) to: Ib. morenoi from Prado del Rey (type locality), Casarabonela, Setenil, and El Chorro, and Ib. cf. morenoi from Félix and El Marchal de Antón López. Radular measurements (Table IV) belong to type locality specimens. Males and females studied and measured were collected in the following months: March, April, October, and November.

Etymology

Dedicated to Dr. Diego Moreno, for his contribution to field collection and study of Iberian Hydrobiidae .

Diagnosis

Shell valvatiform (rarely planispiral); operculum almost circular without peg; the oesophagus makes a loop near the cerebral commissure; rectum strongly U-shaped; male genitalia with a slender penis having a non-glandular penial lobe located in a medial position; female genitalia with a well-developed bursa copulatrix and two seminal receptacles; distal seminal receptaculum elongated and proximal one lying over the widened part of the renal oviduct; central tooth of the radula with one basal cusp on each side.

Description

Shell shape valvatiform (Figure 2A–C, E, G; Table I), sometimes planispiral in Félix and Casarabonela populations, with less than 3.5 whorls (Figure 2J, K); shells from type locality are completely transparent making it possible to follow the position of the intestine; body whorl well-developed measuring 6/7 of total shell length; 1.5 protoconch whorls, total width and nucleus width are 316 and 142 Mm, respectively (Figure 2L–N); pitted or malleated protoconch microsculpture (Figure 2O–Q); wide umbilicus, 0.4 mm in diameter (Figure 2H, I); outer peristome simple, thin, and straight (Figure 2D, F).

Operculum thin, pliable, corneous, paucispiral, circular with a large and central nucleus ( Figure 3A–G ; Table II); its muscle attachment area is rounded.

Body: head scarcely pigmented ( Figure 4F ); tentacles with scarce black pigmentation around the eyes until the middle part of the tentacles; snout about as long as wide, parallelsided, with a medium distal lobation; buccal mass can be seen by transparency; ciliary fields located in the pallial edge ( Figure 3K ).

Nervous system ( Figure 4A, B ) with a very short suboesophageal and a mid-sized supraoesophageal connective; the oesophagus makes a complete loop posterior to the cerebral commissure; nervous system measurements are: length of the right cerebral ganglia: 0.19 mm; length of the right pleural ganglion: 0.06 mm; length of the left pleural ganglion: 0.06 mm; length of the supraoesophageal ganglion: 0.04 mm; length of the suboesophageal ganglion: 0.06 mm; length of the pleurosuboesophageal connective: 0.01 mm; length of the pleurosupraoesophageal connective: 0.06 mm. RPG ratio is 0.36.

Ctenidium with 6–12 well-developed lamellae ( Figure 4C ), occupying three-quarters of the length of the pallial cavity; osphradium 50–60% of ctenidium length, bean-shaped, two to three times longer than broad (Table III).

Posterior stomach chamber smaller than the anterior one ( Figure 4D ; Table V); style sac protrudes anteriorly to the intestinal loop; rectum strongly U-shaped ( Figure 4E ) but tending to S-shaped in Almería populations.

Radula taeniaglossate, long (0.4%) relative to maximum shell dimension; its central tooth has one basal cusp on each side ( Figure 3H ; Table IV); distance between internal

Figure 2. Shells of Iberhoratia morenoi (A, B, D, I, L, O) and Ib. cf. morenoi (C, E–H, J, K, M, N, P, Q). (A, B, D, I, L, O) Shells from Prado del Rey; (C, F, G, H, M, P) shells from Félix; (E, J, K, N, Q) shells from El Marchal de Antón López. (A) Holotype; (L–N) protoconch; (P, Q) detail of the microsculpture from the protoconch and teleoconch. Scale bar: 500 Mm (A–K).

cusps is 8.3 Mm, approximately; its central denticle is long and tapered, followed on each side by four long and tapered denticles in decreasing order of size; basal tongue V-shaped; lateral teeth with three to six denticles on each side of the central one; denticles from the internal marginal teeth approximately equal in size to those of the external marginal teeth ( Figure 3I, J ).

Male genitalia with a large, bean-shaped prostate gland (Table VI; Figure 4E ); seminal vesicle leans over the posterior chamber of the stomach; penis small, slender, with an unpigmented non-glandular penial lobe located in a medial position ( Figures 3L , 4F ); the penis is black pigmented near its tip, except for males from Almería populations which have an orangish pigmentation; penial duct runs straight near the outer edge of the penis.

Female genitalia with a renal oviduct making a tight S-shaped circle which leans over the albumen gland ( Figure 4G ); ovary occupies approximately 75% of visceral mass; more than 50% of the oviduct glands (albumen + capsule glands) (Table III) are located inside the pallial cavity without narrowing; relative size of oviduct can vary between populations: albumen gland is larger than capsule gland in type locality ( Figure 4G ; Table VII), but smaller in other populations examined; bursa copulatrix large and oval, with a mediumsized narrow duct, protruding posterior to albumen gland; the origin of bursal duct is anteroventral; distal seminal receptacle (SR1) large and elongated with a short stalk protruding from renal oviduct in the middle between the oviduct fold and the point where the bursa copulatrix duct joins the oviduct; proximal seminal receptacle (SR2) difficult to identify as it tightly lies over a widened part of the renal oviduct ( Figure 4H ), having the characteristic refringent colour when it is full of sperm.

Remarks

This species is distributed over an extended area in which populations are very much fragmented. This wide geographic area may lend itself to intraspecific differences. In this way, populations from Almería show more depressed shells, a penis with orangish pigmentation, a rectum loop which looks more S-shaped than U-shaped and smaller digestive and genital organs. Nevertheless, the general shape of anatomical characters for all populations is very conservative. In these populations, it is frequent to find an egg capsule located inside the umbilicus of the shell of both male and female specimens containing an embryo in different developmental stages.

Figures

Figure 1. Iberian Iberhoratia populations.

Figure 3. Opercula, radula, and penis of Iberhoratia morenoi (E–G, I, K, L), and Ib. cf. morenoi (A–D, H, J). (A, C, H, J) Opercula from Félix; (B, D) opercula from El Marchal de Antón López; (E, F, G, I, K, L) opercula and radula from Prado del Rey; (L) head of a male and penis from El Chorro. (A, B, E) External side of the operculum; (C, D, F, G) internal side of the operculum; (H, I) central teeth; (J) lateral, internal, and external marginal teeth; (K) ciliary fields in the pallial edge. Scale bars: 200 Mm (A–G).

Figure 4. Anatomy of Iberhoratia morenoi from type locality. (A, B) Partial nervous system; (C) osphradium and ctenidium; (D) stomach; (E) prostate and rectum; (F) head of a male and penis; (G) anterior female genitalia; (H) bursa copulatrix and seminal receptacles. Abbreviations in text. Scale bar: 500 Mm.