• DOI:10.1007/S00227-008-1064-2
• Corpus ID: 84521816

Population dynamics, reproduction and growth of the Indo-Pacific horned sea star, Protoreaster nodosus (Echinodermata; Asteroidea)

@article{Bos2008PopulationDR,
  title={Population dynamics, reproduction and growth of the Indo-Pacific horned sea star, Protoreaster nodosus (Echinodermata; Asteroidea)},
  author={Arthur R. Bos and Girley S. Gumanao and Joan C. E. Alipoyo and Lemuel T. Cardona},
  journal={Marine Biology},
  year={2008},
  volume={156},
  pages={55-63}
}

• A. Bos, G. S. Gumanao, +1 author Lemuel T. Cardona
• Published 8 October 2008
• Environmental Science
• Marine Biology

The horned sea star (Protoreaster nodosus) is relatively common in the Indo-Pacific region, but there is little information about its biology. This study of the population biology of P. nodosus was carried out in Davao Gulf, The Philippines (7°5′N, 125°45′E) between September 2006 and May 2008. Protoreaster nodosus was found in sand and seagrass dominated habitats at a mean density of 29 specimens per 100 m2 and a mean biomass of 7.4 kg per 100 m2, whereas a significantly lower density and biomass was found in coral and rock dominated habitats. Adult specimens (mean radius R = 10.0 cm) were found at depths of 0–37 m, whereas juveniles (R < 8 cm) were only found in shallow sandy habitats with abundant seagrass (water depth ≤2 m). Increased gonad weights were found from March to May (spawning period), which coincided with an increasing water temperature and a decreasing salinity. Density and biomass did not change significantly during reproduction, but sea stars avoided intertidal habitats. All specimens with R > 8 cm had well developed gonads and their sex ratio was 1:1. Protoreaster nodosus grew relatively slowly in an enclosure as described by the exponential function G = 7.433 e−0.257 × R. Maturing specimens (R = 6–8 cm) were estimated to have an age of 2–3 years. Specimens with a radius of 10 cm (population mean) were calculated to have an age of 5–6 years, while the maximum age (R = 14 cm) was estimated as 17 years. Potential effects of ornamental collection on the sea star populations are discussed.