Heterobranch sea slugs from Blanes (Costa Brava, NE Spain)

Manuel Ballesteros 1, 2 & Miquel Pontes 2
1 Emeritus Professor, Universitat de Barcelona, mballesteros@ub.edu
2 VIMAR, Vida Marina

Abstract

The coast of Blanes represents the southern entrance to the famous Catalan Costa Brava, a rugged, steep and very jagged rocky coast, with numerous inlets with beaches of coarse sand and which meanders for just over 200 km up to the French border. Its extraordinary submerged fauna and flora have attracted numerous SCUBA divers from all over the world for decades. Sea slugs in a broad sense (formerly “opisthobranchs”) from the Blanes coast have been studied for more than 40 years by researchers of the University of Barcelona. In this work we present a compilation of the biodiversity of sea slugs cited in the coast of Blanes and observed or collected since 1976 to the present day. We also present the results of an unpublished work carried out at Punta de Santa Anna on a rocky wall located off the Blanes port breakwater, where quantitative visual censuses of sea slug populations were carried out for 14 months, analyzing their absolute abundance, the distribution of the species during the different seasons of the year and the biodiversity index of the different censuses. In total, 139 species of sea slugs have been determined to live on the Blanes coast, making this locality one of the best known for this type of fauna on all the Iberian coast.

Introduction

Blanes is a small village located at 65 km North of Barcelona, Spain. It is the southern limit of the famous “Costa Brava” that runs from Blanes to the north, for more than 100 km, until the French border. Possibly one of the richest hard bottom marine communities from the western Mediterranean are located at the Costa Brava littoral, specially at the Medes Islands (Ros et al., 1984). Being Blanes the Costa Brava diving spot nearest to Barcelona, and the fact that it holds the CEAB (Centre d´Estudis Avançats de Blanes) scientific station, made the marine hard and soft bottoms off Blanes ones the best known for the whole Catalonia coast (Bibiloni, 1980; Pinedo et al., 1997; Sardá et al., 1999).

The “opisthobranch” fauna of Catalan coast (NE Spain) begins to be well known since the 1970´s when several scientists conduct systematic samplings mainly as research for their PhD (Ros, 1973; Ballesteros, 1980). Subsequently, other researchers have emerged from the so-called citizen science and Internet platforms (M@re Nostrum; GROC; OPK) dedicated to the biodiversity of these mollusks that have greatly increased their knowledge. These samplings have allowed the Catalan littoral to be the best known of biodiversity “opisthobranch” fauna (257 different species, Ballesteros et al., 2016) from the whole Spanish Iberian littoral. Just one of these groups of «opisthobranchs», the nudibranchs, accounts for more than 150 species already known in Catalan waters (Ballesteros et al, 2019).

Some studies on the biodiversity of “opisthobranchs” in specific localities have been carried out on the Catalan coast (NE Spain): Ballesteros (1984) who reported 21 species in the locality of Cubelles (Costa Daurada); Domènech et al. (2002) carried out in Port Lligat (Cadaqués, N Costa Brava), where they recorded 45 species; Dacosta et al. (2010) who recorded a total of 48 different species in Es Caials (Cadaqués, N Costa Brava); Ballesteros et al. (2015) with 94 species recorded at PNMMBT Marine Protected Area (L’Estartit, Girona, Spain); Parera et al. (2020), who observed 73 species in the coastline of the city of Barcelona or VIMAR Vida Marina research group unpublished records, accounting for 110 species at PNMMBT Marine Protected Area (L’Estartit, Girona, Spain) in 2023.

In the case of “opisthobranchs” more than 40 years of collecting samples at the Punta de Santa Anna and the very close Cala Sant Francesc, both from the Blanes littoral, together with specimens collected in the extensive commercial trawling grounds off Blanes (Domènech et al., 2006) and the specimens from the malacological collection of Lluís Dantart (Toll & Ballesteros, 2017) have permitted to us to list 139 “opisthobranch” species, meaning that 54% of all the known species for the whole Catalan littoral (Ballesteros et al. 2016) are recorded in just one locality.

Although sea slugs have been intensively studied in numerous coastal or marine areas in all oceans, few studies have been carried out at an ecological level in specific areas. To point out, for example, the work by Miller (1962) on the life cycles of some intertidal nudibranchs on the Isle of Man (U.K.), the extensive work by Nybakken (1978) on the ecology of intertidal nudibranch populations off the coast of California, or that of Goddard et al. (2020, 2021) who carried out a twelve-year long study on the abundance and presence of marine heterobranch species in a couple of locations of the Californian coast. There are no known data on subtidal ecological studies dedicated to “opisthobranchs”.

Here we present the list of the “opisthobranch” species that have been recorded or collected in Blanes littoral and the results of an unpublished quantitative study about the ecology of “opisthobranch” populations throughout a year cycle, made in a sublittoral sciophyllic vertical wall from 0 to 10 m depth.

In this article, the term “opisthobranchs” is repeatedly cited, which is the traditional taxonomic name applied to sea slugs in a broad sense. For the last two decades, and with the knowledge provided by molecular biology, the different groups of «opisthobranchs» have been integrated into the Gastropoda subclass of Heterobranchia. For the nomenclature and taxonomy of the different species, we follow the proposals indicated in the WoRMS (2023) database.

Methodology

The “opisthobranchs” species in the present list have been collected and/or observed:

  • By scuba diving at the Punta Santa Anna and the Cala Sant Francesc between 0 and 30 m depth, both in sporadic scuba dives or monthly sampling dives throughout a whole year in a sciophilic vertical wall at Punta de Santa Ana (Figure 1).
  • By collection of algae substrates and the subsequent study in the laboratory for small and/or cryptic specimens.
  • By commercial fishing arts at the trawling grounds off Blanes at depths between 50 and 300 m.
  • Data from records of species from scientific or citizen science publications and Internet that are contrasted in the Banc de Dades de Biodiversitat de Catalunya (BIOCAT) or in different Internet pages.

Captured specimens were transferred to the laboratory of the Department of Evolutionary Biology, Ecology and Environmental Sciences (formerly the Department of Animal Biology) of the Faculty of Biology of the University of Barcelona to be identified, studied and photographed alive. They were then preserved in 70% alcohol and deposited in the collections of the Animal Biodiversity Resource Center of the Universitat de Barcelona (CRBA). Some specimens of the most interesting or little-known species were dissected to extract their radula, which was prepared for observation under a scanning electron microscope (SEM Scanning) using the standard method (drying the radula in air, mounting it in a metallic stub and coating it with a thin layer of gold or carbon).

The specimens were photographed underwater in their natural environment using various cameras (Nikonos V, Olympus Camedia C50, Olympus XZ1) and in the laboratory with a Konica Minolta Dynax 7 and a 100 mm macro lens.

Figure 1. Situation of Blanes in the Iberian Peninsula and location of sampling points by scuba diving

Faunistic results

A total of 139 “opisthobranch” species have been recorded in the bibliography, Internet or collected/observed by the author in the last 40 years at littoral SCUBA dives or at trawling grounds off Blanes. Of these, 2 belong to Acteonimorpha, 14 to Cephalaspidea, 4 to Pteropoda, 1 to Runcinida, 5 to Aplysiida, 10 to Sacoglossa, 1 to Umbraculida, 7 to Pleurobranchida, and 95 to Nudibranchia (40 Doridina and 55 Cladobranchia). The list with all the species mentioned in the Blanes coast is found in Table 1.

Table 1. List of species registered in Blanes in alphabetical order by taxonomical groups

ACTEONIMORPHAFacelina bostoniensis (Couthouy, 1838)
Acteon tornatilis (Linnaeus, 1758)Facelina rubrovittata (A. Costa, 1866)
Japonactaeon pusillus (Forbes, 1844)Facelinopsis marioni (Vayssière, 1888)
CEPHALASPIDEAFavorinus branchialis (Rathke, 1806)
Aglaja tricolorata Renier, 1807Felimare bilineata (Pruvot-Fol, 1953)
Bulla striata Bruguière, 1792Felimare fontandraui (Pruvot-Fol, 1951)
Camachoaglaja africana (Pruvot-Fol, 1953)Felimare orsinii (Vérany, 1846)
Cylichna cylindracea (Pennant, 1777)Felimare picta (R. A. Philippi, 1836)
Gastropteron rubrum (Rafinesque, 1814)Felimare tricolor (Cantraine, 1835)
Hermania scabra (O. F. Müller, 1784)Felimare villafranca (Risso, 1818)
Melanochlamys miqueli (Pelorce, Horst & Hoarau, 2013)Felimida binza (Ev. Marcus & Er. Marcus, 1963)
Philine quadripartita Ascanius, 1772Felimida krohni (Vérany, 1846)
Philinopsis depicta (Renier, 1807)Felimida luteorosea (Rapp, 1827)
Retusa crossei (Bucquoy, Dautzenberg & Dollfus, 1886)Felimida purpurea (Risso, 1831)
Retusa mammillata (R. A. Philippi, 1836)Flabellina affinis (Gmelin, 1791)
Scaphander lignarius (Linnaeus, 1758)Geitodoris planata (Alder & Hancock, 1846)
Scaphander punctostriatus (Mighels & C. B. Adams, 1842)Hancockia uncinata (Hesse, 1872)
Volvulella acuminata (Bruguière, 1792)Janolus hyalinus (Alder & Hancock, 1854)
RUNCINIDAJorunna tomentosa (Cuvier, 1804)
Runcina adriatica T. E. Thompson, 1980Kaloplocamus ramosus (Cantraine, 1835)
PTEROPODALomanotus marmoratus (Alder & Hancock, 1845)
Cavolinia inflexa (Lesueur, 1813)Luisella babai (Schmekel, 1972)
Clio cuspidata (Bosc, 1801)Marionia blainvillea (Risso, 1818)
Clio pyramidata Linnaeus, 1767Nemesignis banyulensis (Portmann & Sandmeier, 1960)
Cymbulia peronii Blainville, 1818Okenia elegans (Leuckart, 1828)
NUDIBRANCHIAParaflabellina ischitana (Hirano & T. E. Thompson, 1990)
Aegires leuckartii Vérany, 1853Pelagella castanea (Alder & Hancock, 1845)
Aegires palensis Ortea, Luque & Templado, 1990Peltodoris atromaculata Bergh, 1880
Aeolidiella alderi (Cocks, 1852)Phyllidia flava Aradas, 1847
Aldisa banyulensis Pruvot-Fol, 1951Platydoris argo (Linnaeus, 1767)
Amphorina farrani (Alder & Hancock, 1844)Polycera quadrilineata (O. F. Müller, 1776)
Antiopella cristata (Delle Chiaje, 1841)Polycerella emertoni A. E. Verrill, 1880
Armina maculata Rafinesque, 1814Rostanga rubra (Risso, 1818)
Armina neapolitana (Delle Chiaje, 1824)Spurilla neapolitana (Delle Chiaje, 1841)
Armina tigrina Rafinesque, 1814Taringa faba Ballesteros, Llera & Ortea, 1985
Baptodoris cinnabarina Bergh, 1884Tenellia adspersa (von Nordmann, 1845)
Berghia coerulescens (Laurillard, 1832)Tethys fimbria Linnaeus, 1767
Calmella cavolini (Vérany, 1846)Thordisa filix Pruvot-Fol, 1951
Caloria elegans (Alder & Hancock, 1845)Trapania lineata Haefelfinger, 1960
Candiella manicata (Deshayes, 1853)Trapania maculata Haefelfinger, 1960
Candiella odhneri (J. Tardy, 1963)Trinchesia albopunctata Schmekel, 1968
Candiella plebeia (G. Johnston, 1828)Trinchesia caerulea (Montagu, 1804)
Candiella striata (Haefelfinger, 1963)Trinchesia foliata (Forbes & Goodsir, 1839)
Carminodoris boucheti Ortea, 1979Trinchesia genovae (O'Donoghue, 1926)
Carronella pellucida (Alder & Hancock, 1843)Trinchesia miniostriata Schmekel, 1968
Coryphella lineata (Lovén, 1846)Trinchesia ocellata Schmekel, 1966
Cratena peregrina (Gmelin, 1791)Tritonia hombergii Cuvier, 1803
Crimora papillata Alder & Hancock, 1862APLYSIIDA
Dendrodoris grandiflora (Rapp, 1827)Aplysia depilans Gmelin, 1791
Dendrodoris limbata (Cuvier, 1804)Aplysia fasciata Poiret, 1789
Diaphorodoris alba Portmann & Sandmeier, 1960Aplysia punctata (Cuvier, 1803)
Diaphorodoris luteocincta (M. Sars, 1870)Notarchus punctatus R. A. Philippi, 1836
Diaphorodoris papillata Portmann & Sandmeier, 1960Petalifera petalifera (Rang, 1828)
Discodoris stellifera (Vayssière, 1903)SACOGLOSSA
Doridacean sp.1Elysia timida (Risso, 1818)
Doriopsilla areolata Bergh, 1880Elysia translucens Pruvot-Fol, 1957
Doriopsilla pelseneeri d'Oliveira, 1895Elysia viridis (Montagu, 1804)
Doriopsilla rarispinosa Pruvot-Fol, 1951Ercolania coerulea Trinchese, 1892
Doris ocelligera (Bergh, 1881)Hermaea bifida (Montagu, 1816)
Doris pseudoargus Rapp, 1827Hermaea paucicirra Pruvot-Fol, 1953
Doris sticta (Iredale & O'Donoghue, 1923)Hermaea variopicta (A. Costa, 1869)
Doris verrucosa Linnaeus, 1758Placida cremoniana (Trinchese, 1892)
Doto cervicenigra Ortea & Bouchet, 1989Placida dendritica (Alder & Hancock, 1843)
Doto coronata (Gmelin, 1791)Thuridilla hopei (Vérany, 1853)
Doto dunnei Lemche, 1976UMBRACULIDA
Doto eireana Lemche, 1976Umbraculum umbraculum ([Lightfoot], 1786)
Doto floridicola Simroth, 1888PLEUROBRANCHIDA
Doto koenneckeri Lemche, 1976Berthella aurantiaca (Risso, 1818)
Doto paulinae Trinchese, 1881Berthella ocellata (Delle Chiaje, 1830)
Doto rosea Trinchese, 1881Berthella perforata (R. A. Philippi, 1844)
Edmundsella pedata (Montagu, 1816)Berthellina edwardsii (Vayssière, 1897)
Eubranchus exiguus (Alder & Hancock, 1848)Pleurobranchaea meckeli (Blainville, 1825)
Facelina annulicornis (Chamisso & Eysenhardt, 1821)Pleurobranchus membranaceus (Montagu, 1816)
Facelina auriculata (O. F. Müller, 1776)Pleurobranchus testudinarius Cantraine, 1835

Most of these are common and well-known species in the Mediterranean that live on rocky substrates, under stones, between algae or hydrozoans and have a wide geographic distribution. The three species of Armina, A. neapolitana, A. maculata and A. tigrina and the cephalaspidean Gastropteron rubrum are common species that inhabit sandy or muddy circalittoral bottoms like the commercial trawling grounds located off Blanes. Pteropoda species correspond to shells accumulated in marine sediments and have not been observed in vivo. Nevertheless, other species are very little known at the Catalan coast or in the Mediterranean Sea such as Baptodoris cinnabarina, Placida cremoniana, Carminodoris boucheti. Aegires leuckartii, Taringa faba, Thordisa filix, Doris ocelligera, Okenia elegans, Kaloplocamus ramosus, Lomanotus marmoratus and Camachoaglaja africana and more information is needed for understanding their biology and distribution.

 

Ecology of Heterobranch seaslugs populations along a year cycle

Between April 1991 and May 1992 monthly visual “opisthobranch” censuses were made in the so-called Punta de Santa Anna, very close to the breakwater of the port of Blanes (Figure 1). Censuses were made by two divers through scuba diving in a sciophyllic sublittoral vertical wall from 0 to 10 m depth (Figure 2). In each month three quantitative vertical transects 1 m wide were made in the sub littoral wall during the same dive. The total surface sampled each month was 30 m2.

Figure 2. Structure of the sampled vertical wall and characteristics of the main species of algae and invertebrates that occur in it

Figure 2. Structure of the sampled vertical wall and characteristics of the main species of algae and invertebrates found.

 

In total 993 individuals of “opisthobranchs” have been censed belonging to 21 different species, 1 Sacoglossa (Thuridilla hopei), 9 Doridina (Diaphorodoris papillata, Diaphorodoris luteocincta, Polycera quadrilineata, Trapania lineata, Felimare villafranca, Felimare orsinii,  Felimida krohni, Felimida binza), and 11 Cladobranchia (Edmundsella pedata, Flabellina affinis, Trinchesia caerulea, Trinchesia ocellata, Trinchesia genovae, Cratena peregrina, Calmella cavolinii, Facelinopsis marioni, Facelina auriculata, Facelina annulicornis and Candiella manicata).

The “opisthobranch” community of the sublittoral wall is dominated by the Nudibranchia with the Cladobranchia group as the most abundant, with 789 individuals recorded that means the 79,45 % of all the observed specimens, followed by the Doridina with 200 individuals (20,14%) and the Sacoglossa (4 individuals, 0,40%).

Regarding abundances, four species of Cladobranchia stand out with more than a hundred individuals recorded (Trinchesia ocellata, Edmundsella pedata, Cratena peregrina, Trinchesia caerulea) and another two that are close to a hundred individuals (Calmella cavolinii, Facelinopsis marioni). The abundance of Cladobranchia is linked with the abundance of hydrozoans in the wall. The list of all the species and their abundances is in the Table 2.

 

Table 2. List of the species along the year cycle by number of individuals and percentage of the total number of individuals

Trinchesia ocellata162 ind.16,31%
Edmundsella pedata142 ind.14,39&
Cratena peregrina117 ind.11,78%
Trinchesia caerulea110 ind.11,07%
Calmella cavolinii97 ind.9,76%
Facelinopsis marioni77 ind.7,75%
Diaphorodoris papillata55 ind.5,53%
Polycera quadrilineata53 ind.5,33%
Flabellina affinis44 ind.4,43%
Diaphorodoris luteocincta35 ind.3,52%
Candiella manicata28 ind.2,81%
Felimare orsinii26 ind.2,61%
Felimare villafranca15 ind.1,51%
Facelina auriculata11 ind.1,10%
Felimida binza7 ind.0,70%
Felimida krohni6 ind.0,60%
Thuridilla hopei4 ind.0,40%
Trapania maculata2 ind.0,20%
Trapania lineata1 ind.0,10%
Facelina annulicornis1 ind.0,10%

The distribution of the number of individuals appeared along the months show an irregular distribution related with the known demographic rising of some species that have more than one generation along the year (Figure 3) and also due to the presence or absence of the specific food in the environment. The maximum abundance of individuals occurs in the month of April 1991, where 155 specimens are counted, mainly due to the extraordinary abundance of Trinchesia ocellata, with more than 70 specimens registered in the total of the three transects, and also of Cratena peregrina; in both cases their abundance was possibly due to the favorable conditions in that month for the development of hydrozoan colonies (Lafoea sp. and Eudendrium sp., respectively) that are their food. A good abundance of specimens is also observed in the month of August, where some species such as Calmella cavolinii, Cratena peregrina and Trinchesia caerulea reach their maximum abundance throughout the year (Figure 6). The maximum abundances of Diaphorodoris papillata are observed during the winter months.

Taking into account the abundance of individuals in the surface sampled in the three transects (30 square meters) for each month, the densities of individuals are usually higher than 2 ind/m2 in 7 of the months, with a maximum of 5.16 ind/m2 in April 1991 and a minimum of 1.06 ind/m2 in the month of October (Figure 3). Taking into account the 14 months sampled and the number of individuals registered in total, the global density in the sampled wall turns out to be 2.36 ind/m2.

figure3Figure 3. Abundances of specimens by months and transects. The upper part of the graph shows the total numbers of individuals of the three transects and their abundance per square meter. T1, T2 and T3 correspond to the three transects of each month carried out on the sampled vertical wall.

 

The number of species observed in each month is less variable, generally between 9-11 species, with a minimum of 8 (October 1991) and maximum of 14 (April and June of 1992) (Figure 4).

figure4Figure 4. Number of species by month and transect. The upper part of the graph shows the total number of species observed in each month. T1, T2 and T3 correspond to the three transects of each month carried out on the sampled vertical wall.

 

The Shannon-Weaver diversity index (Figure 5) values fluctuate between 2,651 (May 1991) and 3,346 (February 1992), with a mean of 2,961 and a variance of 0,233.

figure5Figure 5. Shannon-Weaver diversity by month and transect. The upper part of the graph shows the total value of each month obtained by calculating the mean value of the three transects. T1, T2 and T3 correspond to the three transects of each month carried out on the sampled vertical wall.

 

The graphics of the abundance distribution along the year of the seven dominants species are shown in the following graphs (Figure 6). It can be observed that these dominant species are present during almost every month of the year with fluctuations in the number of individuals on very marked occasions that could be related to the presence or not of their species/food, with the cryptic character on the substratum of some of them or simply by the chance of its observation.

figure6

Figure 6. Abundances of the seven dominant species throughout the year in the studied vertical wall.

 

Discussion

Most of the “opisthobranch” species recorded for Blanes are common and well-known species that live on rocky bottoms, under stones, between algae or hydrozoans and have a wide geographic distribution. Nevertheless, other species are little known along the Catalan coast such as Baptodoris cinnabarina, Placida cremoniana, Carminodoris boucheti. Aegires leuckartii, Taringa faba, Runcina adriatica, Doris ocelligera, Okenia elegans and Camachoaglaja africana and more information is needed for understanding their biology. Especially interesting, because they are little known, are the species that inhabit circalittoral bottoms and that can only be captured by indirect methods like commercial trawling, such as the three Armina species, which live on soft sand and muddy bottoms.

Despite the limitations in time of SCUBA diving sampling and accepting that some cryptic or very small “opisthobranchs” cannot be observed in a visual census, the results of sampling on the vertical wall show that on this sciophyllic wall some nudibranchs populations are well established and living all over the year, mainly cladobranch species that feed on the abundant hydrozoan colonies that grow on the wall. The abundance and Shannon-Weaver values are high if they are compared with other malacological community studies (Huelin, 1981; Martin et al., 1990). With regard to the general abundance of individuals in the transects, the short life cycle of some species must also be taken into account, which influences the number of individuals recorded each month.

The work that by methodology and geographical proximity is closest to that carried out in Blanes is that of Doménech et al. (2002). These authors carried out a two-year spatial and temporal study (1997-1998) on the “opisthobranch” fauna of the shallow sublittoral of Portlligat (N of the Costa Brava), in a mixed photophilous substrate of rocks and Posidonia oceanica bed. In a surface area of 15 square meters sampled each month they found a total of 138 specimens of 26 different species throughout the two years of its study. Half of the species registered in this work correspond to Doridina species, which are common on the underside of the stones, the most abundant being Aldisa banyulensis, Dendrodoris limbata and Paradoris indecora. The authors did not provide data on the biodiversity indices of the different samplings, possibly due to the low number of specimens registered, but they do record a total of 45 species living in this very small locality, taking into account previous studies and other qualitative samplings.

Although not strictly comparable with our study, the 40-month study by Nybakken (1978) in an area of 250 square meters of the intertidal zone of Asilomar Beach in California indicates the presence of just over 4,000 specimens belonging to 31 species, of which 9 correspond to 87% of the total number of individuals registered in the census; in that study, the number of species and specimens per month also presents large oscillations due to environmental factors and the cycle of the species, with Brillouin (H) diversity values between 1.1 and 2.45, with an average value of all the months of 1.80.

The data obtained in our quantitative study and taking into account the sampled area (30 square meters) and time (14 months) indicate the presence of a rich and diverse community of “opisthobranchs” on the sampled vertical wall. To our knowledge, the present work provides the first data on individual densities in an ecological study on «opisthobranchs».

The high number of species (139) recorded in a single locality could support the idea that possibly Blanes, located between the rocky Costa Brava to the north and the sandy beaches of the Maresme region to the south, is an ecotone and a hotspot for “opisthobranch” biodiversity. The expansion of the wharf of the fishing port of Blanes carried out after our study could have negatively affected to the marine communities from the surroundings and by extension also the “opisthobranch” populations.

 

Plates

Fig.1

Plate 1: A. Facelina annulicornis; B. Thuridilla hopei; C. Facelina auriculata; D. Felimida krohni; E. Felimida binza; F. Trapania lineata; G. Trapania maculata
Picture C by Miquel Pontes, all other pictures by Manuel Ballesteros

 

Fig.2

Plate 2: A. Trinchesia ocellata; B. Edmundsella pedata; C. Cratena peregrina; D. Calmella cavolinii; E. Polycera quadrilineata; F. Trinchesia caerulea; G. Diaphorodoris papillata; H. Facelinopsis marioni
All pictures by Manuel Ballesteros

 

Fig.3

Plate 3: A. Aglaja tricolorata; B. Gastropteron rubrum; C. Runcina adriatica; D. Doto floridicola; E. Discodoris stellifera; F. Phyllidia flava; G. Aldisa banyulensis; H. Berthella perforata; I. Doris ocelligera; J. Candiella striata.
All pictures by Manuel Ballesteros

 

 

 

Acknowledgements

Anna Domènech has collaborated with numerous records of individuals on the Blanes coast and also with the sampling of «opisthobranchs» among the «bruticia» (bycatch) of the commercial trawling vessels in the Port of Blanes. David Vallvé, participated in the monthly surveys of the visual transects on the vertical wall of Punta de Santa Anna. Thanks to the divers of the so-called citizen science who have contributed, with their photographs displayed on different web pages, to the knowledge of the fauna of «opisthobranchs» of the Blanes coast.

 

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Note to readers: This article has not been peer-reviewed and everything in it is the sole responsibility of the authors.

 

 

 

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Manuel Ballesteros
Manuel Ballesteros
Licenciado en Ciencias Biológicas por la Universidad de Barcelona en 1975, obteniendo el grado de Doctor en 1980 en la misma Universidad. Desde 1984 fue Profesor Titular de Zoologia en la Facultad de Biologia de Barcelona, donde impartió las asignaturas de Zoologia General de 1º, Invertebrados de 3º, Zoologia Aplicada de 4º y asignaturas de doctorado relacionadas con la biodiversidad de invertebrados marinos y la gestión de invertebrados terrestres y marinos. Profesor Emérito de la Universidad de Barcelona desde 2023. Especialista en el estudio de los moluscos opistobranquios desde 1975, ha publicado más de 50 articulos científicos y divulgativos sobre ellos. Ha participado en numerosos proyectos de investigación y campañas de muestreo en aguas del mar Mediterráneo, Atlántico, Caribe y en la Antártida. Ha impartido numerosas conferencias y cursos sobre moluscos opistobranquios, invertebrados de la Antártida, invertebrados del Mediterráneo y moluscos en general. Buceador desde 1976, socio fundador del Club d’Immersió Biologia (CIB), ha realizado más de 1.300 inmersiones en el Mediterráneo, Atlántico, Índico, Caribe, Pacífico y en la Antártida; experto en fotografia submarina, vídeo submarino y uso de robot submarino (ROV). Recientemente jubilado, dedica todo su tiempo a escribir sobre su pasión: el mar y la vida marina.
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Miquel Pontes
Miquel Pontes
Informático de profesión, es fotógrafo submarino y naturalista aficionado. Submarinista desde 1994, su “logbook” cuenta con centenares de inmersiones en el mar Mediterráneo, mar Caribe y mar Rojo y en los océanos Atlántico, Índico y Pacífico. Fundador del Grupo de Estudios M@re Nostrum en 1996, socio fundador de Grup de Recerca en Opistobranquis de Catalunya en 2010, socio fundador del Grup de Recerca VIMAR (Vida Marina) en 2012. Co-autor y webmaster del web dedicado a los moluscos opistobranquios del Mediterráneo e Iberia OPK - Opistobranquis, co-autor del libro "Els nudibranquis del mar català" publicado en 2020 por Brau Edicions, descubrió el interesante mundo de los opistobranquios en 1997 de la mano de sus compañeros de inmersión y desde entonces ha sido una línea de trabajo continuada, aportando fotos submarinas, observaciones hechas en el medio natural y colaborando en la difusión de este área del conocimiento. Autor y co-autor de múltiples publicaciones científicas sobre moluscos opistobranquios (y otros grupos animales), ha participado y participa en todo tipo de proyectos divulgativos (libros, revistas, webs, conferencias, exposiciones …) como medio para difundir su interés principal: proteger los mares y los seres que los habitan. Desde 2019 es coordinador del grupo VIMAR (Vida Marina) y es webmaster de esta página web.

Manuel Ballesteros

Licenciado en Ciencias Biológicas por la Universidad de Barcelona en 1975, obteniendo el grado de Doctor en 1980 en la misma Universidad. Desde 1984 fue Profesor Titular de Zoologia en la Facultad de Biologia de Barcelona, donde impartió las asignaturas de Zoologia General de 1º, Invertebrados de 3º, Zoologia Aplicada de 4º y asignaturas de doctorado relacionadas con la biodiversidad de invertebrados marinos y la gestión de invertebrados terrestres y marinos. Profesor Emérito de la Universidad de Barcelona desde 2023. Especialista en el estudio de los moluscos opistobranquios desde 1975, ha publicado más de 50 articulos científicos y divulgativos sobre ellos. Ha participado en numerosos proyectos de investigación y campañas de muestreo en aguas del mar Mediterráneo, Atlántico, Caribe y en la Antártida. Ha impartido numerosas conferencias y cursos sobre moluscos opistobranquios, invertebrados de la Antártida, invertebrados del Mediterráneo y moluscos en general. Buceador desde 1976, socio fundador del Club d’Immersió Biologia (CIB), ha realizado más de 1.300 inmersiones en el Mediterráneo, Atlántico, Índico, Caribe, Pacífico y en la Antártida; experto en fotografia submarina, vídeo submarino y uso de robot submarino (ROV). Recientemente jubilado, dedica todo su tiempo a escribir sobre su pasión: el mar y la vida marina.

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