© Sociedad Española de Malacología Iberus, 30 (1): 53-66, 2012 New species of neogastropods from the islands of the Gulf of Guinea, West Africa Nuevas especies de neogasterópodos de las islas del golfo de Guinea, África occidental Emilio ROLÁN* and Sandro GORI** Recibido el 26-V-2011. Aceptado el 28-X-2011 ABSTRACT Material collected from a recent expedition by the second author (SG) to Principe Island in the Guinean Gulf is studied. Material from nearby islands that was waiting for publication is also included. The new species proposed here belong to the genera Anachis (1 species) and Mitrella (1 species) in the family Columbellidae, and Mitromorpha (3 species) in the family Mitromorphidae, superfamily Conoidea. RESUMEN Se estudia el material recogido en una reciente expedición del segundo autor (SG) a la isla de Príncipe en el Golfo de Guinea. Al tiempo se incorpora material de otras islas pró- ximas que estaba pendiente de publicación. Los géneros estudiados en los que se inclu- yen las nuevas especies encontradas han sido Anachis (una especie) y Mitrella (una espe- cie) de la familia Columbellidae, y Mitromorpha (tres especies) de la familia Mitromorphidae, superfamilia Conoidea. INTRODUCTION In recent years the second author ous paper (ROLÁN &BOYER, 2001), but (SG) made several trips to the islands of has now been examined again and com- the Guinean Gulf, during which a num- pared with the new material collected, ber of samples were collected. When enabling us to reach new conclusions re- these were examined, a few new species garding its status, which leads us to de- were found. In the present paper we de- scribe here a further two new species. scribe the ones belonging to the families Columbellidae Swainson, 1840 (genera Abbreviations used: Anachis and Mitrella) and Mitromorphi- dae Casey, 1904 (genus Mitromorpha) af- MHNS Museo de Historia Natural de la ter the recent systematic changes in Universidad, Santiago de Compostela BOUCHET,KANTOR,SYSOEV &PUILLAN- MNCN Museo Nacional de Ciencias DRE (2011). On the other hand, material Naturales, Madrid, Spain collected on a previous trip by the first MNHN Muséum National d’Histoire author (ER), was mentioned in a previ- Naturelle, Paris, France * Museo de Historia Natural, Universidad de Santiago, Campus Universitario Sur, 15782 Santiago de Compostela, Spain ** Via Sernesi, 7, 57123 Livorno, Italia 53 Iberus, 30 (1), 2012 MCZ Museum of Comparative Zoology, CMS collection of Manuel Suárez, Cambridge, USA Ferrol, Spain NHMUK Natural History Museum, CPR collection of Peter Ryall, Maria London, England Rain, Austria CFS collection of Francisco Sicilia CSG collection of Sandro Gori, Livorno, Guillén, Arrecife, Spain Italia SYSTEMATIC PART Family COLUMBELLIDAE Swaison, 1840 Genus Anachis H. & A. Adams, 1853 H. & A. ADAMS (1858) defined the lecting trips made by many malacolo- genus Anachis in the following terms: gists to several countries in the area, it is “Shell ovately-fusiform; spire elevate, curious to point out that in the revisions whorls longitudinally ribbed; aperture and other papers published over the last narrow; columella straight; outer lip 10 years (ROLÁN &LUQUE, 2002; somewhat rectilinear, crenate inter- HERNÁNDEZ &BOYER, 2005; PELORCE & nally”. Thirteen species are known in BOYER, 2005; ROLÁN, 2005; ROLÁN & the Eastern Atlantic region (including BOYER, 2006; PELORCE &ROLÁN, 2007; the Macaronesian Archipelagos, the ROLÁN & DE OLIVEIRA, 2008; HORRO & Mediterranean and the West African ROLÁN, 2010; SEGERS,SWINNEN & DE coast). PRINS, 2009), seven new species were Some species of this genus in West described or studied: Only in one case Africa were described long ago, the first (PELORCE &BOYER, 2005), however, are being Anachis cuspidata Marrat, 1877. we to find two species together in this Not many more species were found genus, the others having been described over the years and by the end of the always individually. XXth century, only five more had been Since most species have a paucispi- described, the latest being Anachis ral protoconch, presumably their geo- avaroides Nordsieck, 1975. All of these graphical range is small. Only Anachis species were described singly and they avaroides seems to have a larger distribu- have mostly a limited geographical tion area in the Macaronesian archipela- range. As the result of the frequent col- gos. Anachis xani spec. nov. (Figs. 1-6) Type material: Holotype (Figs. 1-3) in MNHN (24819); Paratypes in the following collections: MNCN (15.05/60002, 1 s, Fig. 4); MHNS (100561, 2 s); NHMUK (1); CPR (1); CSG (9). Other material examined: 10 shells eroded or without protoconch, and 17 fragments from the type locality. Type locality: Tinhosa Pequena, 01º22.52’N, 07º16.53’E, under rocks, 25 m, Principe Island. Etymology: The species is named after Juan Manuel “Xan” Guerra, who is in charge of the shell collections of the Museo de Historia Natural “Luis Iglesias”, University of Santiago de Com- postela. Description: Shell (Figs. 1-4) solid, smooth but with spiral micro striae (Fig. broadly fusiform with a moderate high 6) and usually coloured with brown and spire. Protoconch (Fig. 5) with 1 ½ whitish bands. Teleoconch of 4 ½ whorls, sharply pointed and about 0.5 slightly convex whorls, with a distinct mm in maximum diameter, apparently suture and a very small subsutural 54 ROLÁN AND GORI: New species of neogastropods from the islands of the Gulf of Guinea 1 3 2 4 6 200 µm 5 Figures 1-5. Anachis xani spec. nov. 1-3: holotype, 5.0 mm (MNHN); 4: paratype, 5.5 mm (MNCN); 5: apex and protoconch of the holotype; 6: detail of the micro sculpture. Figuras 1-5. Anachis xani spec. nov. 1-3: holotipo, 5,0 mm (MNHN); 4: paratipo, 5,5 mm (MNCN); 5: ápice y protoconcha del holotipo; 6: detalle de la microescultura. 55 Iberus, 30 (1), 2012 shelf. Sculpture formed by axial ribs, numerous, and it lacks spiral sculpture. badly defined subsuturally, a little irreg- It is known from the Azores, Madeira, ular, with variable interspaces, about 20 Selvagem Islands and Canaries. in the two first whorls; in the last whorl, Anachis valledori Rolán & Luque, about 15-19 can be observed, but on the 2002 has a smaller and narrower shell, last quarter of the whorls, they are narrow and elongate axial ribs, variable almost entirely faded. There are no clear but not ocellated colouration. Endemic spiral threads, but under high magnifi- to Cape Verde Islands. cation numerous micro striae can be Anachis ryalli Rolán, 2005 has a seen: about 10 on first whorl, 13-15 on larger and narrower shell, of uniform the second and about 24-28 on the third. tan color, the protoconch is more ele- Towards the base about 12-13 well vated, spiral threads only noticeable in marked striae form evident cords. Aper- the intervals. Collected in Ghana. ture narrow and axially elongate, Anachis delamarrei Rolán & Boyer, usually with 6 teeth on the inner part of 2006 has a smaller shell, protoconch the external lip, the upper ones being with more whorls, fewer axial ribs and larger. Columella curved, S-shaped, it lacks spiral sculpture. Colour uni- with 2 denticles usually almost unno- formly dark brown. Known from ticeable. Shell colour brownish with a Gabon. pattern of numerous ocellae which are a Anachis delineata Rolán & de little larger below the suture, mainly on Oliveira, 2008 has a larger shell, with the last quarter of the shell. few axial ribs; the colouration comprises Soft parts, operculum and radula bands with an ocellated pattern alternat- unknown. ing with others with white blotches. Dimensions: The holotype is 5.0 mm; Known from the Cape Verde Islands. the largest paratype reaches 6.0 mm. Anachis juani Horro & Rolán, 2010 Distribution: Only known from has a shell with strong axial sculpture Principe Island. but fewer ribs; the spiral cords are Remarks: The differences with previ- strong, about 20 on the last whorl; it ously known species are as follows: lacks an ocellated pattern and has a Anachis cuspidata (Marrat, 1877) has a light band on the last whorl. It is from larger (about 7-8 mm) shell, the coloura- Angola. tion is very variable, the ocellated Mitrella annobonensis Rolán, 2005 is pattern very uncommon. Known from rather similar, having less axial sculp- Senegal. ture, less white spots, ¼ shorter proto- Anachis avaroides Nordsieck, 1975 has conch with different microsculpture (see a larger and wider shell, variable in ROLÁN, 2005: fig. 138-139). Perhaps this colouration but usually lacking an ocel- species, due to its axial ribs, could be lated pattern; the axial ribs are not placed in Anachis better than in Mitrella. Genus Mitrella Risso, 1826 Remarks: In the same previously lata (Gmelin, 1791) which reaches the mentioned works in which Anachis West Atlantic coast, or Mitrella melvilli species were described, species of the Kudsen, 1956 from the West African genus Mitrella also appeared. This genus coast, which have a multispiral proto- includes a larger number of species, and conch. Most of the species, however, like about 30 are presently known for the Mitrella broderipi (Sowerby, 1844) from area that includes Mediterranean, Mac- the Mediterranean and the Macarone- aronesian and West African shores. In sian archipelagos, have a short paucispi- this genus, there are species with large ral protoconch and several of these are distribution ranges, such as Mitrella ocel- endemic to small areas. 56 ROLÁN AND GORI: New species of neogastropods from the islands of the Gulf of Guinea Mitrella siciliai spec. nov. (Figs. 7-9) Type material: Holotype (Fig. 7) in MNHN (24820). Paratypes in the following collections: MNCN (15.05/60003, 1 s, Fig. 8), MHNS (100562 , 1 s), NHMUK (1 s), CFS (1); CPR (1); CSG (3 s, Fig. 9). Type locality: Tinhosa Pequena, 01º 20.33’ N, 07º 17.35’ E, under rocks, 25 m, Principe Island.