spongiforme; and the crinoid Antedon mediterranea (Rodríguez and Cabrera 2002;
Luque and Templado 2004; Rueda et al. 2009a). Some of these species, such as the
hippolytids or the gastropods S. viridis, are perfectly adapted to live in and between
the leaves, because their shape and colour (or transparency) give them an amazing
ability to camouflage. In addition, some species, such as hippolytid shrimps, are able
to modify their coloration according to the colour scheme of the leaves and that of
the epiphytes that cover them. Generally, these species were not dominant, but they
characterized these habitats and show interesting biological traits (Cobos et al. 2005,
2011; Manjón-Cabeza et al. 2009, 2011). For example, the neritid S. viridis shows a
strong association with this plant, feeding on the younger epidermal tissues and
preferring this species against other small seagrasses (e.g. Cymodocea nodosa)
(Rueda and Salas 2007; Rueda et al. 2011). Among the fishes, Opeatogenys gracilis,
endemic to the Mediterranean Sea and south of Portugal, is linked to the leaf stratum
of this and other seagrasses and currently represents the smallest teleost of the
Mediterranean Sea (Luque and Templado 2004: 152). The demersal community
was mainly composed of cephalopods (e.g. Sepia elegans, Sepietta oweniana,
Sepiola affinis) and about 70 fish species (dominating the syngnathids Nerophis
ophidion and Syngnathus spp.) (Luque and Templado 2004). In general, the specific
richness and abundance of the demersal and epibenthic fauna increased in both small
seagrasses during the summer and autumn, and especially during the night, and
showed a strong positive correlations with the leaf biomass (García Raso et al. 2006;
Rueda and Salas 2008; Rueda et al. 2008).
The sediment colonized by Z. marina commonly harboured infaunal anthozoans,
such as Cereus pedunculatus, Condylactis aurantiaca and Cerianthus
membranaceus; the sedentary polychaetes Sabella spallanzanii, Spiochaetopterus
sp., Myxicola infundibulum or Lanice conchilega; the scavenger gastropods Tritia
pygmaea and T. reticulata; and the bivalves Moerella distorta, Tellina fabula,
Lucinella divaricata or Solemya togata, the latter in partially anoxic sediments
with a high content of organic matter from certain areas of the seagrass meadow
(Luque and Templado 2004; González et al. 2007; Rueda and Salas 2008). The
infaunal species presented peaks of abundance in autumn, with bivalve species
(e.g. Moerella distorta and Tellina fabula) that reached high densities (~2000 ind/
m
2 ) and displayed a strong correlation with the organic matter content of the
sediment (Rueda and Salas 2008). Among the decapods, the dominant species
were Philocheras echinulatus and pagurids such as Diogenes pugilator. Echinoderms (e.g. Astropecten aranciacus, Coscinasterias tenuispina, Sphaerechinus
granularis, Holothuria tubulosa) are similar to those present in C. nodosa meadows,
including species that are also common in the adjacent soft bottoms (Luque and
Templado 2004).
In fact, the specific composition and structure of these communities associated
with Z. marina or Cymodocea nodosa are quite influenced by that of the surrounding
habitats, with much connectivity between vegetated and unvegetated soft bottoms.
Therefore the structure of the communities varies significantly depending on the
seagrass phenology and diel or seasonal movements of the mobile species (Rueda
et al. 2008; Mateo-Ramírez et al. 2015, 2018).
324
J. L. Rueda et al.
Luque and Templado 2004; Rueda et al. 2009a). Some of these species, such as the
hippolytids or the gastropods S. viridis, are perfectly adapted to live in and between
the leaves, because their shape and colour (or transparency) give them an amazing
ability to camouflage. In addition, some species, such as hippolytid shrimps, are able
to modify their coloration according to the colour scheme of the leaves and that of
the epiphytes that cover them. Generally, these species were not dominant, but they
characterized these habitats and show interesting biological traits (Cobos et al. 2005,
2011; Manjón-Cabeza et al. 2009, 2011). For example, the neritid S. viridis shows a
strong association with this plant, feeding on the younger epidermal tissues and
preferring this species against other small seagrasses (e.g. Cymodocea nodosa)
(Rueda and Salas 2007; Rueda et al. 2011). Among the fishes, Opeatogenys gracilis,
endemic to the Mediterranean Sea and south of Portugal, is linked to the leaf stratum
of this and other seagrasses and currently represents the smallest teleost of the
Mediterranean Sea (Luque and Templado 2004: 152). The demersal community
was mainly composed of cephalopods (e.g. Sepia elegans, Sepietta oweniana,
Sepiola affinis) and about 70 fish species (dominating the syngnathids Nerophis
ophidion and Syngnathus spp.) (Luque and Templado 2004). In general, the specific
richness and abundance of the demersal and epibenthic fauna increased in both small
seagrasses during the summer and autumn, and especially during the night, and
showed a strong positive correlations with the leaf biomass (García Raso et al. 2006;
Rueda and Salas 2008; Rueda et al. 2008).
The sediment colonized by Z. marina commonly harboured infaunal anthozoans,
such as Cereus pedunculatus, Condylactis aurantiaca and Cerianthus
membranaceus; the sedentary polychaetes Sabella spallanzanii, Spiochaetopterus
sp., Myxicola infundibulum or Lanice conchilega; the scavenger gastropods Tritia
pygmaea and T. reticulata; and the bivalves Moerella distorta, Tellina fabula,
Lucinella divaricata or Solemya togata, the latter in partially anoxic sediments
with a high content of organic matter from certain areas of the seagrass meadow
(Luque and Templado 2004; González et al. 2007; Rueda and Salas 2008). The
infaunal species presented peaks of abundance in autumn, with bivalve species
(e.g. Moerella distorta and Tellina fabula) that reached high densities (~2000 ind/
m
2 ) and displayed a strong correlation with the organic matter content of the
sediment (Rueda and Salas 2008). Among the decapods, the dominant species
were Philocheras echinulatus and pagurids such as Diogenes pugilator. Echinoderms (e.g. Astropecten aranciacus, Coscinasterias tenuispina, Sphaerechinus
granularis, Holothuria tubulosa) are similar to those present in C. nodosa meadows,
including species that are also common in the adjacent soft bottoms (Luque and
Templado 2004).
In fact, the specific composition and structure of these communities associated
with Z. marina or Cymodocea nodosa are quite influenced by that of the surrounding
habitats, with much connectivity between vegetated and unvegetated soft bottoms.
Therefore the structure of the communities varies significantly depending on the
seagrass phenology and diel or seasonal movements of the mobile species (Rueda
et al. 2008; Mateo-Ramírez et al. 2015, 2018).
324
J. L. Rueda et al.