Preprint volume - SIBM

Pre-print Volume – Posters
AQUACULTURE COMMITEE
A. FABBROCINI, R. D’ADAMO
Consiglio Nazionale delle Ricerche, Istituto di Scienze Marine, UOS Lesina, Via Pola, 4 - 71010 Lesina (FG),
Italia.
adele.fabbrocini@fg.ismar.cnr.it
HISTOLOGICAL EXAMINATION OF THE GONADS OF
PARACENTROTUS LIVIDUS (LMK, 1816) FROM THE SOUTHERN
ADRIATIC COAST
ANALISI ISTOLOGICA DELLE GONADI DI PARACENTROTUS LIVIDUS
(LMK, 1816) PROVENIENTI DALLE COSTE DELL’ADRIATICO MERIDIONALE
Abstract – The histological evaluation of the gonads of Paracentrotus lividus (Echinodermata: Echinoidea)
has been carried out from April to November on specimens sampled along the mid-to-low Adriatic coast.
The % of individuals with gonads in active gametogenesis never decreased until 50% also in summer
months, when a resting period would be expected. This continuous presence of individuals with an active
gametogenesis is very useful in order to set up rearing protocols for a short-term induction of gonad yield
and gamete maturation.
Key-words: sea urchin, Paracentrotus lividus, gonad histology, Gonad Index, reproduction.
Introduction - In the last years the interest in developing cost-effective ways of
culturing sea urchins has increased as the world’s wild stocks of many species have
been affected by unregulated exploitation and by other anthropic activities (Guidetti et
al., 2003); this is particularly true for Paracentrotus lividus (Lmk, 1816), a macroalgivore
sea urchin commonly living along the North Atlantic coasts and throughout
the Mediterranean sea (Sánchez-España et al., 2004), highly valued for its edible
gonads and whose gametes and embryos are commonly used as a model in
developmental biology research and as test-species in ecotoxicological bioassays.
Rearing protocols for the short-term induction of gamete maturation need to take into
account the different initial reproductive conditions of the sea urchin specimens. As the
pattern of gonadal growth of P. lividus living in relatively contiguous areas has been
reported to differ in relation to food availability (Byrne, 1990), aim of this work was
the histological evaluation of the gonadal growth of P. lividus from the Southern
Adriatic coast, in order to identify the period in which specimens having early
developing gametes may be collected for an easier induction of the resumption of
gametogenesis by manipulating food quality and quantity under controlled rearing
conditions.
Materials and methods – Twenty P. lividus adult specimens (horizontal diameter >35
mm) were hand-collected with the aid of Scuba from the rocky seabed near Termoli
(41°54’N; 16°10’ E), on the southern Adriatic coast at 6 wk interval from April to
November. On their arrival in laboratory, urchins were allowed to drip for 5min,
weighed (0.2 mg accuracy) and then dissected; the gonads were extracted and fresh
weighed for Gonad Index evaluation: GI = gonads wet weight (g)/urchin wet weight
(g) ×100. One of the five gonads of each animal was fixed in 10% formalin, embedded
in paraffin, sectioned at 7 µm and stained with Mayer’s Haemalum/Eosin; the
reproductive stage was assigned to each using the nomenclature of Spirlet et al., 1998:
stage I (spent with relict gametes), stage II (spent empty), stage III (recovery), stage
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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