Maldonado 2014). As examples can be mentioned Jaspis eudermis and Axinella
vellerea, previously only known from Azores and a Norwegian fiord, or
Hemiasterella elongata, previously known only from its holotype collected in the
Cape Verde Islands.
On the other hand, one of the most peculiar groups within the phylum Porifera is
that formed by carnivorous sponges, all belonging to the family Cladorhizidae
(Hestetun et al. 2016). Contrary to the aquiferous system used to filter water for
particulate matter characteristic of this primitive phylum, the carnivorous sponges
have developed the ability to trap prey items coupled with the complete or partial
reduction of the aquiferous system. In the Mediterranean, these peculiar sponges are
represented by two species: Cladorhiza abyssicola and Lycopodina hypogea. The
former is a bathyal sponge widely distributed in the NE Atlantic that has been found
in deeper waters of a few locations of the NW Mediterranean (Vacelet 1969) and one
specimen in the Alboran Sea (Boury-Esnault et al. 1994). Meanwhile, L. hypogea
was originally described (as Asbestopluma hypogea) from shallow submarine caves
(15–25 m depth) in the Western Mediterranean Sea and the Adriatic (Vacelet and
Boury-Esnault 1996; Bakran-Petricioli et al. 2007). Nonetheless this species has
subsequently been observed in some deep Mediterranean and Atlantic locations
(in the depth range 100–500 m), among them in the Seco de los Olivos (Aguilar
et al. 2011b, at 167 m) and Cabliers Seamount (Chevaldonné et al. 2015, between
370 and 400 m) on the north and south margins, respectively, of the Alboran Sea.
10.2.2 Cnidaria
The small and semitransparent anemone Sideractis glacialis is mainly known in
northern latitudes of the East Atlantic, usually in deep white coral banks. It was
recorded in the NW Mediterranean by den Hartog et al. (1993) and more recently by
Aguilar and Marín (2013) in some seamounts near the Balearic Islands and in the
Seco de los Olivos. Due to its small size and inconspicuous colour, this species may
often have been overlooked. The Mediterranean records reveals that it is more
widely distributed than has previously been assumed, and its distributional range
possibly coincides to a large extent with that of white coral banks formed by
Desmophyllum pertusum and Madrepora oculata.
The large scyphozoan jellyfish Drymonema dalmatinum was described from the
Dalmatian coast in the Adriatic Sea. Despite its conspicuous size, this medusa has
been very rarely observed. Malej et al. (2014) reported an increased frequency of
sightings in the last 15 years from the Adriatic and eastern Mediterranean Sea, and
recently Kienberger and Prieto (2016) reported a single specimen observed and
photographed by scuba divers near La Herradura (S Spain) at a depth of 12 m,
with a bell diameter of approximately 70 cm.
Dendrobrachia bonsai (Fig. 10.4) is a delicate and small gorgonian whose
whitish and inconspicuous colonies usually do not exceed 10 cm in height. This
species was recorded by Zibrowius and Taviani (Zibrowius and Taviani 2005) as
10 Invertebrates: The Realm of Diversity
367
vellerea, previously only known from Azores and a Norwegian fiord, or
Hemiasterella elongata, previously known only from its holotype collected in the
Cape Verde Islands.
On the other hand, one of the most peculiar groups within the phylum Porifera is
that formed by carnivorous sponges, all belonging to the family Cladorhizidae
(Hestetun et al. 2016). Contrary to the aquiferous system used to filter water for
particulate matter characteristic of this primitive phylum, the carnivorous sponges
have developed the ability to trap prey items coupled with the complete or partial
reduction of the aquiferous system. In the Mediterranean, these peculiar sponges are
represented by two species: Cladorhiza abyssicola and Lycopodina hypogea. The
former is a bathyal sponge widely distributed in the NE Atlantic that has been found
in deeper waters of a few locations of the NW Mediterranean (Vacelet 1969) and one
specimen in the Alboran Sea (Boury-Esnault et al. 1994). Meanwhile, L. hypogea
was originally described (as Asbestopluma hypogea) from shallow submarine caves
(15–25 m depth) in the Western Mediterranean Sea and the Adriatic (Vacelet and
Boury-Esnault 1996; Bakran-Petricioli et al. 2007). Nonetheless this species has
subsequently been observed in some deep Mediterranean and Atlantic locations
(in the depth range 100–500 m), among them in the Seco de los Olivos (Aguilar
et al. 2011b, at 167 m) and Cabliers Seamount (Chevaldonné et al. 2015, between
370 and 400 m) on the north and south margins, respectively, of the Alboran Sea.
10.2.2 Cnidaria
The small and semitransparent anemone Sideractis glacialis is mainly known in
northern latitudes of the East Atlantic, usually in deep white coral banks. It was
recorded in the NW Mediterranean by den Hartog et al. (1993) and more recently by
Aguilar and Marín (2013) in some seamounts near the Balearic Islands and in the
Seco de los Olivos. Due to its small size and inconspicuous colour, this species may
often have been overlooked. The Mediterranean records reveals that it is more
widely distributed than has previously been assumed, and its distributional range
possibly coincides to a large extent with that of white coral banks formed by
Desmophyllum pertusum and Madrepora oculata.
The large scyphozoan jellyfish Drymonema dalmatinum was described from the
Dalmatian coast in the Adriatic Sea. Despite its conspicuous size, this medusa has
been very rarely observed. Malej et al. (2014) reported an increased frequency of
sightings in the last 15 years from the Adriatic and eastern Mediterranean Sea, and
recently Kienberger and Prieto (2016) reported a single specimen observed and
photographed by scuba divers near La Herradura (S Spain) at a depth of 12 m,
with a bell diameter of approximately 70 cm.
Dendrobrachia bonsai (Fig. 10.4) is a delicate and small gorgonian whose
whitish and inconspicuous colonies usually do not exceed 10 cm in height. This
species was recorded by Zibrowius and Taviani (Zibrowius and Taviani 2005) as
10 Invertebrates: The Realm of Diversity
367