Growth and secondary production of the shallow-water gorgonian Eunicella singularis were investigated at two infralittoral rocky stations located in the Tyrrhenian Sea (Cannitello and Cape Enfola), separated by a cline of 4 degrees of latitude. Colonies were aged by counting the number of annual growth rings at the base of the skeleton. Mean annual linear growth rates were calculated by fitting a von Bertalanffy growth equation for the species. Growth rates were 3.55 and 4.52 cm yr-1 respectively. The Enfola population exhibited an age structure reflecting a past pulse in recruitment. The Cannitello population exhibited a gamma-type distribution, dominated by younger age classes, thus suggesting a continuous recruitment rate over time. The two population differed also in colony density, which was higher at Enfola. Secondary production was estimated by means of the increment-summation method, and yielded 5.6 and 3.2 g ash-free dry weight (AFDW) m-2 yr-1 for Cannitello and Enfola populations, respectively. P/B ratio was higher at Cannitello, because of the age structure of the population. Strong currents probably cause population density-thinning mechanisms, favouring a more continuous recruitment

Structure, growth and secondary production of two Tyrrhenian populations of the white gorgonian Eunicella singularis (Esper 1791)

MUNARI, Cristina;MISTRI, Michele
2013

Abstract

Growth and secondary production of the shallow-water gorgonian Eunicella singularis were investigated at two infralittoral rocky stations located in the Tyrrhenian Sea (Cannitello and Cape Enfola), separated by a cline of 4 degrees of latitude. Colonies were aged by counting the number of annual growth rings at the base of the skeleton. Mean annual linear growth rates were calculated by fitting a von Bertalanffy growth equation for the species. Growth rates were 3.55 and 4.52 cm yr-1 respectively. The Enfola population exhibited an age structure reflecting a past pulse in recruitment. The Cannitello population exhibited a gamma-type distribution, dominated by younger age classes, thus suggesting a continuous recruitment rate over time. The two population differed also in colony density, which was higher at Enfola. Secondary production was estimated by means of the increment-summation method, and yielded 5.6 and 3.2 g ash-free dry weight (AFDW) m-2 yr-1 for Cannitello and Enfola populations, respectively. P/B ratio was higher at Cannitello, because of the age structure of the population. Strong currents probably cause population density-thinning mechanisms, favouring a more continuous recruitment
2013
Munari, Cristina; G., Serafin; Mistri, Michele
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/1752896
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 9
  • ???jsp.display-item.citation.isi??? 10
social impact