blending Mediterranean species with others belonging to the subtropical fauna of
North-West Africa or to the temperate biota of the European Atlantic. The consequence of this is that its waters are among the most species-rich of all European seas
and are of foremost importance for the preservation of regional biodiversity. The
knowledge about this richness is of importance to the commercial use of Alboran
waters, and the scientific survey effort has been in part associated to this use.
With regard to fish, the general knowledge of Alboran species richness is based
on a long tradition of using sea products of the Alboran Sea, mainly on the European
coast. The Greek geographer Strabo (64 BC-23 AD), in his Geography, mentioned
salted fish from Algeciras, Sexi (Almuñécar), and Malaka (Málaga). The mentioned
salted products were not only tuna, but moray eels, sturgeons or mackerels, and
smaller fish. In more recent times, numerous scientific authors documented a series
of lists of fish that were used in the coasts of the Alboran Sea, especially in its
Spanish slope, among them García de la Leña (which is a pseudonym for Cristobal
Medina Conde) who in 1789 named 139 fish caught in the coasts of Málaga (García
de la Leña [Medina Conde] 1789) and Steindachner (1868) who reported 203 species
from the Spanish coasts of the Alboran Sea.
The investigations on the marine biodiversity of the south of the Alboran Sea did
not start until the twentieth century, when the Biological-Marine Station of Málaga,
from which derived the current Spanish Institute of Oceanography, was created in
1911 by Odón de Buen, according to his words, “due to the scientific importance of
the Strait of Gibraltar”. He organized the first African biological expeditions along
the Rif coast (Melilla-Chafarinas-Cabo Tres Forcas), between 1908 and 1912
(Camiñas 1997; Pérez de Rubín 2011). As a result, the first important works on
the ichthyofauna of the Moroccan side of the Alboran Sea were published by Odón
de Buen (de Buen 1912, 1913, 1926), reporting 127 species, and by Fage (1912),
who collaborated with the taxonomic identification of 82 other species.
In total, 508 species of fish, of which 430 species are bony fish, 75 species are
cartilaginous fish, and 3 species are agnatha, have been historically cited in the
Alboran Sea. The recently published checklist of marine species in Spanish waters
(MAGRAMA 2017) only considered species recently found in Alboran, and reduced
these numbers to 465 species of fish, grouped into 133 families, of which 389 species
are bony fish (108 families), 75 species of cartilaginous fish (24 families) and
1 species of agnatha (1 family). The MAGRAMA (2017) checklist recorded 5409
species of marine fauna and flora as occurring in the “Strait of Gibraltar and
Alboran” demarcation, and another 169 “revisable” species whose presence requires
confirmation. This represents, in a relatively small area, one-third of the total known
species of the Mediterranean Sea (Coll et al. 2010).
A macroecological implication of the biogeographical role of the Strait of Gibraltar and the Alboran Sea as transition zone is that they give place to several spatial
trends in species diversity. In general, marine species richness is known to decrease
bathymetrically from the surface to the deep seabed, latitudinally from the equator to
the poles, and longitudinally in many locally idiosyncratic ways and usually linked
to historical processes (Gray 2001). Due to the effective barrier effect of the shallow
Strait of Gibraltar for deep biota, the bathymetrical gradient in species richness is
444
R. Real et al.
North-West Africa or to the temperate biota of the European Atlantic. The consequence of this is that its waters are among the most species-rich of all European seas
and are of foremost importance for the preservation of regional biodiversity. The
knowledge about this richness is of importance to the commercial use of Alboran
waters, and the scientific survey effort has been in part associated to this use.
With regard to fish, the general knowledge of Alboran species richness is based
on a long tradition of using sea products of the Alboran Sea, mainly on the European
coast. The Greek geographer Strabo (64 BC-23 AD), in his Geography, mentioned
salted fish from Algeciras, Sexi (Almuñécar), and Malaka (Málaga). The mentioned
salted products were not only tuna, but moray eels, sturgeons or mackerels, and
smaller fish. In more recent times, numerous scientific authors documented a series
of lists of fish that were used in the coasts of the Alboran Sea, especially in its
Spanish slope, among them García de la Leña (which is a pseudonym for Cristobal
Medina Conde) who in 1789 named 139 fish caught in the coasts of Málaga (García
de la Leña [Medina Conde] 1789) and Steindachner (1868) who reported 203 species
from the Spanish coasts of the Alboran Sea.
The investigations on the marine biodiversity of the south of the Alboran Sea did
not start until the twentieth century, when the Biological-Marine Station of Málaga,
from which derived the current Spanish Institute of Oceanography, was created in
1911 by Odón de Buen, according to his words, “due to the scientific importance of
the Strait of Gibraltar”. He organized the first African biological expeditions along
the Rif coast (Melilla-Chafarinas-Cabo Tres Forcas), between 1908 and 1912
(Camiñas 1997; Pérez de Rubín 2011). As a result, the first important works on
the ichthyofauna of the Moroccan side of the Alboran Sea were published by Odón
de Buen (de Buen 1912, 1913, 1926), reporting 127 species, and by Fage (1912),
who collaborated with the taxonomic identification of 82 other species.
In total, 508 species of fish, of which 430 species are bony fish, 75 species are
cartilaginous fish, and 3 species are agnatha, have been historically cited in the
Alboran Sea. The recently published checklist of marine species in Spanish waters
(MAGRAMA 2017) only considered species recently found in Alboran, and reduced
these numbers to 465 species of fish, grouped into 133 families, of which 389 species
are bony fish (108 families), 75 species of cartilaginous fish (24 families) and
1 species of agnatha (1 family). The MAGRAMA (2017) checklist recorded 5409
species of marine fauna and flora as occurring in the “Strait of Gibraltar and
Alboran” demarcation, and another 169 “revisable” species whose presence requires
confirmation. This represents, in a relatively small area, one-third of the total known
species of the Mediterranean Sea (Coll et al. 2010).
A macroecological implication of the biogeographical role of the Strait of Gibraltar and the Alboran Sea as transition zone is that they give place to several spatial
trends in species diversity. In general, marine species richness is known to decrease
bathymetrically from the surface to the deep seabed, latitudinally from the equator to
the poles, and longitudinally in many locally idiosyncratic ways and usually linked
to historical processes (Gray 2001). Due to the effective barrier effect of the shallow
Strait of Gibraltar for deep biota, the bathymetrical gradient in species richness is
444
R. Real et al.