MEPS 469:25-36 (2012)  -  DOI: https://doi.org/10.3354/meps09976

Sexual structure of a highly reproductive, recovering gorgonian population: quantifying reproductive output

Roberta Cupido1,5,*, Silvia Cocito1, Valentina Manno2, Sara Ferrando2, Andrea Peirano1, Mimmo Iannelli3, Lorenzo Bramanti4, Giovanni Santangelo5

1ENEA Marine Environment Research Centre, PO Box 224, La Spezia 19100, Italy
2Dip.Te.Ris, V. Benedetto XV 5, Genoa 16132, Italy
3Department of Mathematics, University of Trento, V. Sommarive 14, Povo (Trento) 38123, Italy
4Institut de Ciencias del Mar (CSIC), Passeig Marítim de la Barceloneta 37-49, Barcelona 08003, Spain
5Department of Biology (Zoology), University of Pisa, via A. Volta 6, Pisa 56126, Italy

ABSTRACT: A population of the Mediterranean red gorgonian Paramuricea clavata has exhibited unexpected resilience after being impacted by 2 anomalous mortality events in 1999 and 2003. To understand the recovery mechanisms, we examined the population reproductive structure and reproductive output based on data collected via non-destructive sampling techniques. The overall population sex ratio was balanced, though the spatial distribution of sexes was significantly segregated. Dividing the population into 14 size classes on the basis of their measured average annual growth revealed a decreasing monotonic trend of abundance of larger classes. The Recruitment class was consistently dominant. The minimum size at first reproduction was 8.5 cm in height, corresponding to an age of ~3 yr. The percentage of fertile colonies increased with size, reaching 90% in size Class 9. Polyp fecundity increased with colony size and did not differ significantly between healthy and damaged colonies. As the number of mature oocytes produced by a colony is a function of polyp fecundity and of the number of reproductive polyps, colony reproductive output increased exponentially with size. The population reproductive output (145 × 103 mature oocytes m−2 yr−1) was one-fifth of that measured in stable, undamaged populations and came mainly from the medium size classes. After the catastrophic mortality, the population has been recovering, albeit with reduced reproductive output. Moreover, it has exhibited a 2-fold increase in recruitment rate, 3-fold greater than that measured in other, undisturbed populations. Our findings are consistent with a strict density-dependent recruitment control operating in crowded, stable P. clavata populations.


KEY WORDS: Mass mortality · Northwestern Mediterranean · Octocorals · Paramuricea clavata · Population recovery · Fecundity tables


Full text in pdf format 
Cite this article as: Cupido R, Cocito S, Manno V, Ferrando S and others (2012) Sexual structure of a highly reproductive, recovering gorgonian population: quantifying reproductive output. Mar Ecol Prog Ser 469:25-36. https://doi.org/10.3354/meps09976

Export citation
Mail this link - Contents Mailing Lists - RSS
- -