illuminated environments. Arbacia lixula is more abundant at slightly deeper
waters (1–15 m) and in sciaphilous assemblages, probably having a slightly higher
trophic level than P. lividus. Finally, D. africana is the most abundant species,
reaching densities up to 240 ind. per 100 m
2 covering large extensions of unvegetated rock. It can reach depths up to 100 m. A less abundant species that can
be confused with Diadema is another long-spined sea urchin C. longispinus. The
sea star Hacelia attenuata can also be found on rocky and detritic bottoms.
On rocky substrata, but close to soft bottoms, the holothurians H. (H.) mammata
and Holothuria (Lessonothuria) arguinensis are common. The daily feeding
behavior of these species in Canary Islands has been described by Pérez-Ruzafa and
Marcos (1987). Holothuria (Vaneyothuria) lentiginosa lentiginosa inhabits rocky
and sandy bottoms deeper than 20 m. Holothuria (Panningothuria) forskali has
been collected on rocky substrata at 348 m depth at Tenerife Island (Pérez-Ruzafa
et al. 1987). This is the southernmost and greatest depth reported for the species.
Pérez-Ruzafa (1984) made the first report of the small incubating holothurian
Neocnus incubans in the Atlantic from the Canary Islands, it was always found on
Cystoseira spp. on the upper infralittoral. The small, incubating ophiuroid, Amphipholis squamata, is common in photophilous algae.
The ophiuroid Ophiothrix (Ophiothrix) fragilis, Ophiocomina nigra, Ophiomyxa pentagona and Ophioderma longicauda are common under stones and in
crevices. The nocturnal anfiatlantic apodid holothurian Euapta lappa is common in
cryptic habitats and is particularly abundant in the western part of the archipelago
where the waters are warmer. Other species of ophiuroids on rocky bottoms of the
archipelago are Ophioconis forbesi, Ophioderma appressum, Ophiocoma pumila,
Ophiactis savignyi and Ophiactis virens.
The sea stars Luidia ciliaris and Astropecten aranciacus and the sea urchin
Echinocardium cordatum occur on sandy bottoms. The sea urchin Brissus unicolor, occurs on sandy bottoms under stones. The sea stars Astropecten irregularis
irregularis and Peltaster placenta, the ophiuroids Ophiura (Dictenophiura) carnea
and Ophiura texturata, the sea urchins Genocidaris maculata, Schizaster canaliferus, Spatangus purpureus, Plagiobrissus costai and the holothuroids H. (H.)
mammata and Thyone fusus occur on sandy and muddy bottoms in shallow water
and Eostichopus regalis and Stichopus tremulus in deeper water.
The sea urchin Echinocyamus pusillus and the ophiuroid Ophiura grubei are
common on detrictic bottoms. The ophiuroid Ophiacantha setosa can be found on
gorgonians.
15.3.1 Biogeographic Relationships of the Echinoderm
Fauna of the Canary Islands
The origin of the echinoderm fauna of the Canary Islands is mainly warm-temperate (28 %) and with a wide thermal distribution (26 %) (Fig. 15.9). The strictly
490
J. C. Hernández et al.
waters (1–15 m) and in sciaphilous assemblages, probably having a slightly higher
trophic level than P. lividus. Finally, D. africana is the most abundant species,
reaching densities up to 240 ind. per 100 m
2 covering large extensions of unvegetated rock. It can reach depths up to 100 m. A less abundant species that can
be confused with Diadema is another long-spined sea urchin C. longispinus. The
sea star Hacelia attenuata can also be found on rocky and detritic bottoms.
On rocky substrata, but close to soft bottoms, the holothurians H. (H.) mammata
and Holothuria (Lessonothuria) arguinensis are common. The daily feeding
behavior of these species in Canary Islands has been described by Pérez-Ruzafa and
Marcos (1987). Holothuria (Vaneyothuria) lentiginosa lentiginosa inhabits rocky
and sandy bottoms deeper than 20 m. Holothuria (Panningothuria) forskali has
been collected on rocky substrata at 348 m depth at Tenerife Island (Pérez-Ruzafa
et al. 1987). This is the southernmost and greatest depth reported for the species.
Pérez-Ruzafa (1984) made the first report of the small incubating holothurian
Neocnus incubans in the Atlantic from the Canary Islands, it was always found on
Cystoseira spp. on the upper infralittoral. The small, incubating ophiuroid, Amphipholis squamata, is common in photophilous algae.
The ophiuroid Ophiothrix (Ophiothrix) fragilis, Ophiocomina nigra, Ophiomyxa pentagona and Ophioderma longicauda are common under stones and in
crevices. The nocturnal anfiatlantic apodid holothurian Euapta lappa is common in
cryptic habitats and is particularly abundant in the western part of the archipelago
where the waters are warmer. Other species of ophiuroids on rocky bottoms of the
archipelago are Ophioconis forbesi, Ophioderma appressum, Ophiocoma pumila,
Ophiactis savignyi and Ophiactis virens.
The sea stars Luidia ciliaris and Astropecten aranciacus and the sea urchin
Echinocardium cordatum occur on sandy bottoms. The sea urchin Brissus unicolor, occurs on sandy bottoms under stones. The sea stars Astropecten irregularis
irregularis and Peltaster placenta, the ophiuroids Ophiura (Dictenophiura) carnea
and Ophiura texturata, the sea urchins Genocidaris maculata, Schizaster canaliferus, Spatangus purpureus, Plagiobrissus costai and the holothuroids H. (H.)
mammata and Thyone fusus occur on sandy and muddy bottoms in shallow water
and Eostichopus regalis and Stichopus tremulus in deeper water.
The sea urchin Echinocyamus pusillus and the ophiuroid Ophiura grubei are
common on detrictic bottoms. The ophiuroid Ophiacantha setosa can be found on
gorgonians.
15.3.1 Biogeographic Relationships of the Echinoderm
Fauna of the Canary Islands
The origin of the echinoderm fauna of the Canary Islands is mainly warm-temperate (28 %) and with a wide thermal distribution (26 %) (Fig. 15.9). The strictly
490
J. C. Hernández et al.