|Spatio-temporal variability in a key herbivore, the long-spined black sea urchin (Diadema antillarum, Echinodermata: Echinoidea) in the Canary Islands|
Tuya, F.; Ortega-Borges, L.; Del Rosario-Pínilla, A.B.; Haroun, R.J. (2006). Spatio-temporal variability in a key herbivore, the long-spined black sea urchin (Diadema antillarum, Echinodermata: Echinoidea) in the Canary Islands. J. Mar. Biol. Ass. U.K. 86(4): 791-797
In: Journal of the Marine Biological Association of the United Kingdom. Cambridge University Press/Marine Biological Association of the United Kingdom: Cambridge. ISSN 0025-3154, more
|Authors|| || Top |
- Tuya, F.
- Ortega-Borges, L.
- Del Rosario-Pínilla, A.B.
- Haroun, R.J.
Spatio-temporal variability in the population structure of long-spined black sea urchin, D. antillarum across all counts was 2.70±0.07 ind m-2 (mean± E, N=1440), while the mean biomass was 105.76±3.75 g m-2 (mean±SE, N=1440). Abundances and biomasses of D. antillarum differed consistently between vegetated and unvegetated bottoms; however, locations within each habitat at each island fluctuated following different trends. For the overall study, mean densities and biomasses in the barren locations varied between 3.36-6.97 ind m-2 and 93.76-405.13 g m-2, respectively; while mean densities and biomasses in the algal stand locations varied between 0-0.33 ind m-2 and 0 - 7.34 g m-2, respectively. Striking differences existed in the size-structure among locations; however, larger size-classes (test diameter >3.5 cm) were present at all locations, and usually dominated in terms of abundance. The majority of individuals in the algal stands were large-sized, probably as a result of the high abundance of the most palatable food. In contrast, small-sized individuals (test diameter <1.5 cm) only occurred in the barren habitat, suggesting that recruitment of D. antillarum could be favoured by the presence of high densities of congeners, as a way to decrease the risk of predation.