© Sociedad Española de Malacología Iberus, 19 (1): 7-24, 2001 Eulimid gastropods (Caenogastropoda: Eulimidae) of the Canary Islands. Part I. Species parasiting sea urchins Eulímidos (Caenogastropoda: Eulimidae) de las Islas Canarias. Parte I. Especies parásitas de erizos de mar Myriam RODRÍGUEZ, Jacinto BARQUÍN and Gustavo PÉREZ-DIONIS* Recibido el 11-VII-2000. Aceptado el 22-XI-2000 ABSTRACT The present paper deals with 4 species of eulimid gastropods parasitic on sea urchins: Echi- neulima leucophaes parasite of Diadema antillarum; Vitreolina philippi parasite of Arbacia li- xula, Paracentrotus lividus and Sphaerechinus granularis; and Nanobalcis nana and Sabine- lla bonifaceae both parasites of the sea urchin Cidaris cidaris. A complete description of shell and soft parts of these species along wiht data on lifestyle and infestation rates is provided. RESUMEN Este trabajo versa sobre 4 especies de eulímidos parásitos de erizos de mar: Echineulima leucophaes parásita de Diadema antillarum; Vitreolina philippi parásita de Arbacia lixula, Paracentrotus lividus y Sphaerechinus granularis; y Nanobalcis nana y Sabinella bonifa- ceae ambas parásitas del erizo Cidaris cidaris. Se incluyen descripciones de concha y partes blandas, así como datos sobre su ecología y tasas de infección. KEY WORDS: Mollusca, Gastropoda, Eulimidae, Echineulima leucophaes, Vitreolina philippi, Nanobalcis nana, Sabinella bonifaciae, Tenerife, Canary Islands, NE Atlantic. PALABRAS CLAVE: Mollusca, Gastropoda, Eulimidae, Echineulima leucophaes, Vitreolina philippi, Nanobalcis nana, Sabinella bonifaciae, Tenerife, Islas Canarias, Atlántico NE. INTRODUCTION The Eulimidae is a large family of about 150 from North Atlantic, but few parasitic gastropods. Almost all species of them are known from their host. are parasites on echinoderms and typi- Nevertheless, the species of eulimids are cally have small, glossy, white shells. almost impossible to place in genera if Many are free-living, able to move from the host is unknown, and often difficult one host to another, but some are per- to determine. In many species there is a manently attachet to their host, or have pronounced sexual dimorfism and to become endoparasites. There are pro- some extent the development of the bably thousand species worldwide, shell depends on sex of the animal or on many of them undescribed. According the presence or absence of additional to WARÉN (1984), there have been des- individuals of the same species, which cribed about 850 living species, of which in some of them determine the sex of * Departamento de Biología Animal (Ciencias Marinas), Facultad de Biología, Universidad de La Laguna, C\ Astrofísico Francisco Sánchez s/n. 38206 La Laguna, Tenerife, Spain. 7 Iberus, 19 (1), 2001 Pta. del Hidalgo La Barranquera Las Teresitas Las Aguas Garachico Las Caletillas TENERIFE El Tablado Alcalá ISLAND Las Eras Poris de Abona Playa Paraíso Abades Tajao El Pallmar Pta. la Rasca El Médano Agua Dulce Pta. Salema Figure 1. Sampling localities. Figura 1. Localidades de muestreo. newly settle larvae (WARÉN, 1984). This tion on two species found parasiting the complicates specific classification. A crinoids Antedon bifida (Pennant), and a complete review of the biology and sys- next work will deal whith the species tematic of the family can be seen in the found in sediments. above mentioned work (WARÉN, 1984). The eulimids from the Canary Islands are poorly known. NORDSIECK MATERIAL AND METHODS AND GARCÍA-TALAVERA (1979) included eighteen species of Eulimidae in their The specimens of eulimids studied book on marine molluscs of Madeira and in this paper come from samples of the Canary Islands, mainly based upon the more common littoral species of sea work of WATSON (1897). The status of urchins in the Canary Islands: Paracen- most of these nominal species must be trotus lividus (Lamark), Arbacia lixula questioned in light of recent work. (L.), Sphaerechinus granularis (Lamark) BOUCHET AND WARÉN (1986) in their and Diadema antillarum (Philippi). revision of the northeast Atlantic bathyal Twenty eight samples were taken by and abyssal molluscs described six new scuba diving in eighteen localities of species of Eulimidae near the Canary Tenerife Island (see Figure 1) between 5 Island, between 500 and 850 m in depth. and 35 m in depth. Besides, some In recent year ENGL (1997a, 1997b, 1998) samples of the circalittoral sea urchin has described three new species of euli- Cidaris cidaris (L.) coming from fishing mids in circalittoral bottoms of Puerto nets were studied. These samples were del Carmen, Lanzarote. All these des- caught from some localities of Tenerife, criptions were based upon dead shells. Gran Canaria and Fuerteventura (see An additional paper was published by Table VIII). ENGL (1999) on “Eulima” fuscozonata In the laboratory each specimen of Bouchet and Warén, 1986. sea urchin was carafully examined In recent years we have carried out under a binocular microscope. The living an exhaustive searching for species of specimens of eulimids found in each one Eulimidae, mainly in Tenerife Island. In were recorded and measured. Some spe- a former paper the first author (RODRÍ- cimens were photographied alive an GUEZ, 2000) described the new species others were selected to be observed at Melanella lutea, which parasites the sea scanning electron microscopy. cucumber Holothuria sanctori Delle Voucher material of all the species Chiaje. Here we deal with four species studied was deposited in the Depart- found parasiting sea urchins. In another ment of Animal Biology, La Laguna Uni- paper in this volume we focus our atten- versity, Tenerife. 8 RODRÍGUEZ ET AL.: Eulimids parasiting sea urchins in the Canary Islands RESULTS Family EULIMIDAE Philippi, 1853 Genus Echineulima Lützen and Nielsen, 1975 Echineulima leucophaes (Tomlin and Shackleford, 1913) (Figs. 2, 4-9) Mucronalia leucophaës Tomlin, J. R, le B. and Shackleford, L. J. “Descriptions of new species of Marginella and Mucronalia from São Thomé. The Journal of Conchology,24: 1913-1915. Type locality: São Thomé Material estudied: The number of specimens studied and the localities where they were collected are specify in Table I and Figure 1. Description: Shell solid, white, glossy, behind than the apical union with the translucent, rather globular, sharpened suture. Inner lip slightly swelled apically and last whorl inflated occup- forming a small columelar callosity. ying 2/3 of the shell. Spire straight Size: The specimens studied had a without curvature. Whorls clearly range of 4 to 9 whorls. The measure- convex. Suture very evident because of ments were carried out separating pre- the whorl convexity. Below the suture a viously the males from the females, narrow whitish band is appreciated because of the great difference in size. A which corresponds to the false suture. male of a determinate number of whorls Surface smooth with only growing presents a much smaller size with scars, strongly marked in some shells. respect to a female with the same Protoconch clearly differentiated, number of whorls. Terefore, males have since the larval whorls have a very less whorls inflated and smaller diame- reduced diameter, meanwhile the teleo- ter (Figs. 5, 6). conch diameter increases rapidly. It con- In the 54 specimens measured the sists of three whorls and lacks ornamen- ratio (width/length) ranged from tation or colour that differentiates from 2.44/1.73 mm in a male of 4 whorls to the rest of the shell. Male and female 13.45/7.15 mm in a female of 9 whorls shells have been studied with scanning (Tables II and III). electron microscopy and no significant Soft parts: Soft parts white and differences with respect to their morp- similar in both sexes. Neither spots nor hology were observed (Fig. 2). coloured marks are normally apprecia- Protoconch smooth, increasing ted in the head-foot or mantle. In some slightly its diameter between one whorl specimens small dark spots are seen by and the next. These larval whorls easily transparency in the suture zone and differentiate from those of the teleo- areas slightly yellowish that correspond conch, the diameter of the latter increase to the internal organs. more rapidly, are clearly more convex Tentacles long, fine, sharpened at the and have fine grooves that cross the tip, strong yellow in colour with some whorl perpendicularly with respect to whitish spots on the surface. Tip and the suture. These grooves appear on the ventral zone white. Some animals with shell of both sexes, although in males lighter coloured tentacles were obser- they are more marked. The growing ved, sometimes almost white. scars are very clear. Eyes small, black, located at the base Aperture rounded and large in of the tentacles, with a yellow border. males, and slightly more quadrangular Vision through the shell. in females. Outer lip fine, no terminal Once the animal is in the parasite swelling. In profile almost straight, first position on the host the different parts third part projected faintly and with- of the foot are observed, partially cove- draws ending at the base, further ring the base of the shell. When it is 9 Iberus, 19 (1), 2001 Table I. Material studied of Diadema antillarum and Echineulima leucophaes, and infestation rates. Tabla I. Material estudiado de Diadema antillarum y Echineulima leucophaes, y porcentajes de infección. Nº of specimens Nº of specimens Nº of of D. antillarum of D. antillarum specimens of Locality studied parasited Infestation rates (%) E. leucophaes Abades 100 4 4.0 7 Agua Dulce 180 7 3.9 13 Alcalá 115 1 0.9 1 El Palm-mar 61 1 1.6 2 El Tablado 80 2 2.5 3 La Barranquera 100 0 0.0 0 Las Aguas 30 0 0.0 0 Las Caletillas 290 11 3.8 21 Las Eras 258 5 1.9 10 Playa Paraiso 200 4 2.0 11 Pta. Salema 125 2 1.6 2 Pta. La Rasca 166 2 1.2 4 Punta del Hidalgo 60 0.0 0 Tajao 200 2 1.0 3 _ Total 1.911 41 X = 2.1 77 repeatedly disturbed it withdraws pletely stretched out.