13.2.2 Physiology, Development, and Reproduction
of Pinna nobilis
There has been a limited number of recent studies on the physiology and reproduction of Pinna nobilis (De Gaulejac 1993; Riva 2003). Most of them are due to the
CERAM (Centre d’Etude des Ressources Animales Marines) and to the Institut
oce ´anographique Paul Ricard (Vicente, De Gaulejac, Riva, and coworkers). The
general metabolism of Pinna nobilis, in particular respiration and filtration, seems
to be rather low compared to other bivalves like the mussel, the edible oyster or the
clam (Vicente et al. 1992). To our knowledge, no physiological studies were
performed in relation with shell calcification: in particular, although hemocytes of
Pinna nobilis were precisely described (Henry et al. 1992), no link was established
between the presence of these cells in mantle tissues and the transport of calcium or
of amorphous calcium carbonate granules for shell mineralization.
Pinna nobilis is a successive hermaphrodite, with an asynchronous gamete maturation (De Gaulejac et al. 1995a, b; Vicente 2003), which avoids self-fertilization.
Its sexual cycle is divided into two phases: a sexual repose from October to March,
an active sexual period for the rest of the year, with in particular a succession of
alternate spawning and fast gametogenesis from June to August. Ovocytes are
fertilized in full seawater. After fecondation, the development of P. nobilis follows
the classical developmental pathway for bivalves, namely, a trochophore larval
stage (ciliated larva), and a veliger stage (swimming larva). When the veliger larva
gets fixed of a substratum, the metamorphosis operates (loss of the velum, reorganization of the internal organs), and the larva transforms into a juvenile specimen.
The larval shell starts to be secreted early during development, during the trochophore stage. However, unlike works on other bivalves like Mytilus or Ostrea, there
were no precise studies on the shell ontogeny of P. nobilis.
13.2.3 Systematic Position of Pinna nobilis and Ancestry
of the Pinnid Family
For the taxonomical position of Pinna nobilis within the Mollusca phylum, we refer
to the classification of Giribet (2008), based on morphological and molecular
characters, and to the molecular phylogeny established by Steiner and Hammer
(2000) for Pteriomorphian bivalves. P. nobilis is a bivalve which belongs to
the Pteriomorphia subclass. This heterogeneous clade is nowadays considered
as the sister group of the heteroconchs, which itself comprises paleoheterodont
(freshwater mussels) and heterodont (clams) bivalves. The Pteriomorphia subclass comprises nine superfamilies (Mytiloidea, Pterioidea, Pinnoidea, Arcoidea,
Limoidea, Ostreoidea, Plicatuloidea, Pectinoidea, and Anomioidea, see Steiner
and Hammer 2000), the three first of them being characterized by typical nacroprismatic shell texture. P. nobilis belongs to the Pinnoidea superfamily, and to
13 Acidic Shell Proteins of the Mediterranean Fan Mussel Pinna nobilis
357
of Pinna nobilis
There has been a limited number of recent studies on the physiology and reproduction of Pinna nobilis (De Gaulejac 1993; Riva 2003). Most of them are due to the
CERAM (Centre d’Etude des Ressources Animales Marines) and to the Institut
oce ´anographique Paul Ricard (Vicente, De Gaulejac, Riva, and coworkers). The
general metabolism of Pinna nobilis, in particular respiration and filtration, seems
to be rather low compared to other bivalves like the mussel, the edible oyster or the
clam (Vicente et al. 1992). To our knowledge, no physiological studies were
performed in relation with shell calcification: in particular, although hemocytes of
Pinna nobilis were precisely described (Henry et al. 1992), no link was established
between the presence of these cells in mantle tissues and the transport of calcium or
of amorphous calcium carbonate granules for shell mineralization.
Pinna nobilis is a successive hermaphrodite, with an asynchronous gamete maturation (De Gaulejac et al. 1995a, b; Vicente 2003), which avoids self-fertilization.
Its sexual cycle is divided into two phases: a sexual repose from October to March,
an active sexual period for the rest of the year, with in particular a succession of
alternate spawning and fast gametogenesis from June to August. Ovocytes are
fertilized in full seawater. After fecondation, the development of P. nobilis follows
the classical developmental pathway for bivalves, namely, a trochophore larval
stage (ciliated larva), and a veliger stage (swimming larva). When the veliger larva
gets fixed of a substratum, the metamorphosis operates (loss of the velum, reorganization of the internal organs), and the larva transforms into a juvenile specimen.
The larval shell starts to be secreted early during development, during the trochophore stage. However, unlike works on other bivalves like Mytilus or Ostrea, there
were no precise studies on the shell ontogeny of P. nobilis.
13.2.3 Systematic Position of Pinna nobilis and Ancestry
of the Pinnid Family
For the taxonomical position of Pinna nobilis within the Mollusca phylum, we refer
to the classification of Giribet (2008), based on morphological and molecular
characters, and to the molecular phylogeny established by Steiner and Hammer
(2000) for Pteriomorphian bivalves. P. nobilis is a bivalve which belongs to
the Pteriomorphia subclass. This heterogeneous clade is nowadays considered
as the sister group of the heteroconchs, which itself comprises paleoheterodont
(freshwater mussels) and heterodont (clams) bivalves. The Pteriomorphia subclass comprises nine superfamilies (Mytiloidea, Pterioidea, Pinnoidea, Arcoidea,
Limoidea, Ostreoidea, Plicatuloidea, Pectinoidea, and Anomioidea, see Steiner
and Hammer 2000), the three first of them being characterized by typical nacroprismatic shell texture. P. nobilis belongs to the Pinnoidea superfamily, and to
13 Acidic Shell Proteins of the Mediterranean Fan Mussel Pinna nobilis
357