|Morpho-functional defences of Mediterranean sea urchins, Paracentrotus lividus and Arbacia lixula, against fish predators|
Guidetti, P.; Mori, M. (2005). Morpho-functional defences of Mediterranean sea urchins, Paracentrotus lividus and Arbacia lixula, against fish predators. Mar. Biol. (Berl.) 147: 797-802
In: Marine Biology. Springer: Heidelberg; Berlin. ISSN 0025-3162, more
|Authors|| || Top |
- Guidetti, P., more
- Mori, M.
Morpho-functional features potentially involved in defence mechanisms against fish predators (i.e. attachment tenacity, spine length, and test robustness and thickness) have been assessed in two Mediterranean sea urchins, Paracentrotus lividus and Arbacia lixula. All four morpho-functional features were significantly and positively related to individual size for both species of sea urchins. Test robustness (i.e. static load needed to break sea urchin tests) was significantly greater for A. lixula (from 3,450 to 15,000 g depending on size) than for P. lividus (1,180-11,180 g). Attachment tenacity (i.e. force needed to dislodge sea urchins from the rocky substrate) was greater in A. lixula (280-3,300 g) than inP. lividus (110-1,450 g), and the difference tended to decrease in relation to smaller sea urchin size. Spine length was greater in A. lixula (1.5-2.9 cm) than in P. lividus (0.5-2.3 cm), but the difference decreased for larger sea urchin size. Test thickness was slightly greater (but not significantly) in A. lixula (0.35-1.10 mm) than in P. lividus (0.12-0.90 mm). These results provide evidencethat morpho-functional features of sea urchins could be involved in affecting predation rates by fishes upon P. lividus and A. lixula, with potential implications for the population structure and distribution patterns of the two sea urchins in shallow rocky reefs.