Rifia yacoubii, Ghamizi, 2020

Ghamizi, Mohamed, 2020, New stygobiont genus and new species (Gastropoda, Hydrobiidae) from the Rif (Morocco), Ecologica Montenegrina 31, pp. 50-56 : 52-55

publication ID	https://doi.org/ 10.37828/em.2020.31.11
publication LSID	urn:lsid:zoobank.org:pub:2337247B-C781-4F7D-993B-B0ED1A5DB633
persistent identifier	https://treatment.plazi.org/id/D6DB8B52-4308-445E-8B5E-27784893740C
taxon LSID	lsid:zoobank.org:act:D6DB8B52-4308-445E-8B5E-27784893740C
treatment provided by	Felipe
scientific name	Rifia yacoubii
status	gen. nov.

Treatment

Rifia yacoubii View in CoL n. gen. n. sp.

https://zoobank.org/ urn:lsid:zoobank.org:act:D6DB8B52-4308-445E-8B5E-27784893740C

Description: Shell very small (1-1.2 mm of diameter), valvatiform, almost planispiral, thin, transparent when fresh; surface of protoconch malleated; spire consisting of 3 ¼ - 3 ½ rapidly growing whorls; last whorl large, slightly descending; aperture large, roundish; peristome complete, ticked, slightly reflected at columellar margin; umbilicus wide, about ¼ of shell diameter ( Figs. 2 A,B,D,E View Figure 2 ; Fig. 3A View Figure 3 ). Operculum concave, paucispiral, thin, yellowish pale with well-developed peg at centre of its inner face ( Fig. 2 C View Figure 2 ; Fig. 3 B View Figure 3 ). Body unpigmented; eye spots absent; stomach without posterior caecum; intestine with well-developed U-like bend on pallial wall; ctenidium consisting of 10 - 13 lamellae; osphradium oval ( Figs. 3 G,F View Figure 3 ).

Male genitalia with prostate gland bulging at ¼ into pallial cavity; penis short, cylindro- conical, corrugated near base, pointed near apex, with two well-raised and non-glandular lobes, one on left side, tubular, about ½ of penis length, another, smaller, on ventral- right side about 1/3 of penis length; penial apex without stylet ( Figs. 3 C,D,E,F View Figure 3 ).

Female genitalia with two seminal receptacles, elongated and equal in size; bursa copulatrix arising from renal oviduct, medium size, oval, with slender elongated duct entering bursa on anterior side ( Fig. 3 G,H View Figure 3 ).

Type material: Holotype ( Fig. 2 A View Figure 2 ), deposited at the National Museum of Natural History of Paris ( France) ( MNHN 27110 About MNHN ); paratypes (two shells, Figs. 2 B,D View Figure 2 ; MNHN 27111 About MNHN ); paratypes (16 shells, 5 dissections, Coll. Ghamizi, MHNMR55 F7, 11.5.1993; 6 shells, MHNMR4 , Fakher-Abiari leg. 16.9.1997); paratypes (7 shells, 5 dissections, Coll. Bodon, Italy, Yacoubi-Khebiza & Ghamizi leg. 11.5.1993).

Type locality: Well at 1 km of west of Guercif, near Taniat Labghal; UTM VC 69; altitude= 500 m.; temperature=18°C; conductibility=870 P s/cm; protected well (by a small edge of the ground and by a cover at the top) .

Other sites and material examined

The new species has been collected in eight other wells in addition to the type locality ( Fig. 1 View Figure 1 ). (UTM: Universal Transverse Mercator grid; Alt= Altitude; P= piezometric level in the well; H= height of the water column; Cond= Conductibility; T °= Temperature of the water; Coll.: collection; MHNM: Muséum d’Histoire Naturelle de Marrakech) .

I Well at Oulad Ben Hlima, Mikkes, 15 km NW of Fes ; UTM UC 28 ; P= 5 m; H= 15 m; Cond=960 µs/cm; protected well. 4.5.1993 (5 shells, kept in Coll. Ghamizi, MHNMR1 F2, 2 dissections, MHNMR1 F4)

I Well at Ben Draoua , 18 Km S of Ouezzane; UTM TD74; Alt = 200m ; Cond =1048 µs/cm; P= 3.2 m ; H= 4 m; 4.5.1993 (3 shells, Coll. Ghamizi, MHNMR5 F2)

I Well at Karia Ben Awda , Arbaoua , 40 Km W of Ouezzane; UTM TD16; Alt = 50 m; Cond=975 µs/cm; well without protection. 5.5.1993 (5 shells, Coll. Ghamizi, MHNMR8 F4)

I Well at Guercif; UTM VC78; Alt= 350 m; P= 12 m; H= 2.2 m; T °= 19°C; Cond=990 P s/cm; protected well into a private house. 11.5.1993 (8 shells, 3 dissections, Coll. Ghamizi, MHNMR54 F2)

I Well at Aïn El Behira, Taza; UTM VC48; Alt. 500 m; P= 10 m; H= 1 m; T °= 19°C; Cond= 1800 P s/cm; well without protection. 11.5.1993 (2 shells, Coll. Ghamizi, MHNMR56 )

I Well at Kasbah Beni Hitem, 10 Km E of Taza; UTM VC49; Alt= 500 m; P=5; H= 0.5m; T °=19°C; Cond=2500 P s/cm; well without protection. 11.5.1993. (6 shells, 1 dissection, Coll. Ghamizi, MHNMR 57)

I Well at 10 Km E of Boured, near Azib, (Boured); UTM UD94; Alt= 1160 m; P= 2 m; H= 3 m; T °=14°C; Cond=500 P s/cm; well without protection. 12.5.1993. (2 shells, Coll. Ghamizi, MHNMR 69F4)

I Well at Douar Qbail, near Aïn Aïcha, 5 Km N of Tissa; UTM UD 41; P= 6.9 m; H= 0.3 m. 13.5.1993. (3 shells, Coll. Ghamizi, MHNMR 78F3)

Etymology: species dedicaced to Professor Mohamed Yacoubi-Khebiza (University of Marrakesh), working in subterranean Crustacea of Morocco and having participated in the collection of the stygobiont fauna from wells of the Rif mountains.

Taxonomy and discussion: The European valvatiform hydrobiids sharing penis with lobe(s) and three saclike structures on renal oviduct, a bursa copulatrix and two seminal receptacles (see Radea et al. 2016, Table 2) are: Pseudoislamia Radoman 1978 ; Daphniola Radoman 1973 ; Bracenica Radoman 1973 ; Gocea Hadzisce 1956 ; Karevia Hadzisce 1959 ; Ohrigocea Hadzisce 1959 ; Ohridohauffenia Hadzisce 1959 ; Prespolitorea Radoman 1983 ; Horatia Bourguignat 1887 ; Fissuria Boeters 1981 ; Pezzolia Bodon & Giusti 1986 ; Spathogyna Arconada & Ramos 2002 ; Corbellaria Callot-Girardi & Boeters 2012 ; Iberhoratia Arconada et Ramos 2007 ; Greacoarganiella Falniowski & Szarowska 2011. The new genus Rifia differs from these genera by characters cited below.

Pseudoislamia Radoman 1978 , described from Greece, has operculum without peg, penis with one lobe, small bursa copulatrix. Daphniola Radoman 1973 , described from Greece, has operculum without peg, penis with one lobe, shell valvatiform-globose conical ( Radoman 1973, 1983; Schütt 1980; Bodon et al. 2001). Bracenica Radoman 1973 , described from Montenegro, has penis with one lobe ( Radoman 1973; Radoman 1983). Gocea Hadzisce 1956 , Karevia Hadzisce 1959 , Ohrigocea Hadzisce 1956 , Ohridohauffenia Hadzisce 1959 and Prespolitorea Radoman 1983 , described from Macedonia and Albania (for Prespolitorea ), have operculum without peg (spiralized on outer face in Gocea ), penis with one lobe, distal seminal receptacle rudimentary in Karevia , Ohrigocea and Prespolitorea ; shell partly despiralized ( Gocea ), bicarinate ( Karevia ) or sometimes carinate ( Ohridohauffenia ) (see Bodon et al. 2001, for discussions on taxonomy of these genera). Horatia Bourguignat 1887 , described from Croatia, has operculum without peg, penis with lobe; valvatiform to ovoid shell (see Bodon et al. 2001, for taxonomy discussions about this genus). Fissuria Boeters 1981 , described from France, has operculum without peg, penis with 2-4 glandular lobes ( Boeters 1981; Bodon et al. 2001). Pezzolia Bodon & Giusti 1986 , described from Italy, has operculum without peg, penis with or without glandular lobe(s); bursa copulatrix very reduced or absent ( Bodon & Giusti 1986; Bodon et al. 2001). The presence of multiple papillae found on the propodium of Spathogyna Arconada & Ramos 2002 , is a peculiar characteristic that has not been previously reported in any other hydrobiid ( Arconada & Ramos 2002). Corbellaria Callot-Girardi & Boeters 2012 , described from Spain, has operculum without peg, penis with one lobe; the absence of the ctenidium is reported as a diagnostic character for genus level for Corbellaria ( Callot-Girardi & Boeters 2012) . Iberhoratia Arconada & Ramos 2007 , has operculum without peg, the penis with one non-glandular penial lobe ( Arconada et al. 2007). Greacoarganiella Falniowski & Szarowska 2011, has a penis with one lobe ( Falniowski & Szarowska 2011). Among all these genera, Bracenica has operculum with peg on inner face as the new taxa described here (and spiralized on outer face in Gocea ). In the analytical key for identification of the Hauffenia species, the peg of operculum is variable in shape, reduced or absent ( Bodon et al. 2001, Table 7). It is clear that this character is not diagnostic for genus level. If we do not consider it, two genera cited above having female genitalia with two seminal receptacles and male genitalia with two penial lobes, are Fissuria and Horatia . Fissuria has penis with 3-4 (rarely 2) glandular lobes of variable size and position ( Boeters 1981, Figs.5-8; Bodon et al. 2001, Figs. 24, 30-34); rectum with S-like bend and Horatia has eye spots and rectum without bend (U-like in the new taxa, Fig. 3G View Figure 3 ).

The two valvatoid hydrobiid genera recently described from Morocco and collected from the springs, have pigmented bodies and eye spots ( Glöer et al. 2020b, Figs. 2 View Figure 2 (2), 3(5)); the genus Ifrania Glöer, Mabrouki & Taybi 2020 (Type species: Ifrania zerroukansis Glöer, Mabrouki & Taybi 2020 ) has a long and thin penis without penial lobes and genus Fessia Glöer, Mabrouki & Taybi 2020 (Type species: Fessia aouintii Glöer, Mabrouki & Taybi 2020 ) has a penis described as « flat, relatively thick at the basis with a small bulge and tapered at the distal end» ( Glöer et al. 2020b). Islamia tifertensis Glöer, Mabrouki & Taybi 2020 was collected from a spring and is described only on empty shell ( Glöer et al. 2020a) and assigned to Islamia without known its anatomy; however, hydrobiid species are characterized by the penis and the shell shape ( Szarowska 2006). The new genus Rifia differs quite from the above three valvatoid genera reported from Morocco by its penis with two small non-glandular lobes at mid part of the penis ( Figs. 3 C, D, E View Figure 3 ). This character coupled with the female genitalia with two seminal receptacles ( Figs. 3 G, H View Figure 3 ) and associated with endemic distribution resulting from its poor dispersal capacity and its stygobiont features (depigmented body and no eye spots) suggesting that a new genus should be introduced. The new species Rifia yacoubii n.sp. differs by its almost planispiral shell, that more depressed than in I. tifertensis which anatomical characters and operculum are lacking. I. tifertensis has been collected from a spring as empty shells will be probably a subterranean species. The spring Tifert, type locality of I. tifertensis ( Glöer et al. 2020a) is situated at downstream of the Moulouya basin, at 180 km from the nearest well (type locality) where R. yacoubii has been collected ( Fig. 1 View Figure 1 ). If we consider that is the same phreatic basin (Moulouya basin), I. tifertensis could be assigned to the new genus Rifia as a second species. The genus Islamia Radoman 1973 , having penis bilobed and no bursa copulatrix ( Radoman 1983; Bodon et al. 2001; Arconada & Ramos 2006), should therefore be disregarded, as its presence in Morocco is not yet anatomically confirmed.

Habitat and distribution: All specimens collected are from wells. The new species seems to be widespread in phreatic waters and found, until now, in nine wells along the south border of the Rif region, in the upstream of Moulouya, Sebou and Loukkos basins ( Fig. 1 View Figure 1 ). Specimens collected with whole animal have depigmented bodies, without eye spots and are adapted to groundwater (stygobiont species).

Status: the species is reported as nomina nudum ( Pseudoislamia yacoubii ) and listed as Critically Endangered species (CR) among the threatened freshwater molluscs of North Africa ( Van Damme et al. 2010).

Acknowledgement

Thanks to Pr. Philippe Bouchet and Dr. Serge Gofas who allowed me access and helped me to take pictures by Scanning Electronic Microscopy at MNHN Paris and Dr. Marco Bodon for the anatomical pictures. I thank Dr. Fakher-Abiari for providing me with additional field samples.