TY - JOUR
T1 - New body metrics to determine asteroid size and weight directly in the field.
AU - Gianguzza, Paola
AU - Bonaviri, Chiara
AU - Badalamenti, null
AU - Deidun, Alan
AU - Badalamenti, Fabio
AU - Di Trapani, Francesco
AU - Visconti, Giulia
PY - 2015
Y1 - 2015
N2 - Asteroids are an important group of predators in many marine ecosystems. The measure of body size is crucial in studying asteroid biology as this variable affects both prey selection and predation impact. Current field techniques for estimating asteroid size (i.e. total length TL, total weight TW) include the measure of correlated variables, such us the central disk (CD) and arm length (AL). However, these variables are often time-consuming and require a direct handling of the organism. We tested the accuracy of new asteroid body metrics, the arm height (AH) or arm width (AW), to rapidly estimate body size in asteroids. AH and AW were measured in three of the most common Mediterranean asteroids (Marthasterias glacialis, Ophidiaster ophidianus and Coscinasterias tenuispina), sampled from April to August 2008, along the coasts of Ustica Island off the northern coast of Sicily. We used both linear and exponential regression analyses to compare the performance of AH, AL, AW and CD in estimating size for the three species studied. Results suggest that, in M. glacialis and C. tenuispina, AH is strongly correlated (p<0.001) with both TL and TW, whereas in O. ophidianus it gives a good correlation (p<0.001) with TW only. AW was poorly correlated with both TL and TW in M. glacialis and C. tenuispina, but not in O. ophidianus, where it showed the highest correlation with TW. Thus, only the novel AH measure constitutes a convenient and reliable way of measuring asteroid body size in the field.
AB - Asteroids are an important group of predators in many marine ecosystems. The measure of body size is crucial in studying asteroid biology as this variable affects both prey selection and predation impact. Current field techniques for estimating asteroid size (i.e. total length TL, total weight TW) include the measure of correlated variables, such us the central disk (CD) and arm length (AL). However, these variables are often time-consuming and require a direct handling of the organism. We tested the accuracy of new asteroid body metrics, the arm height (AH) or arm width (AW), to rapidly estimate body size in asteroids. AH and AW were measured in three of the most common Mediterranean asteroids (Marthasterias glacialis, Ophidiaster ophidianus and Coscinasterias tenuispina), sampled from April to August 2008, along the coasts of Ustica Island off the northern coast of Sicily. We used both linear and exponential regression analyses to compare the performance of AH, AL, AW and CD in estimating size for the three species studied. Results suggest that, in M. glacialis and C. tenuispina, AH is strongly correlated (p<0.001) with both TL and TW, whereas in O. ophidianus it gives a good correlation (p<0.001) with TW only. AW was poorly correlated with both TL and TW in M. glacialis and C. tenuispina, but not in O. ophidianus, where it showed the highest correlation with TW. Thus, only the novel AH measure constitutes a convenient and reliable way of measuring asteroid body size in the field.
KW - Coscinasterias tenuispina
KW - Marthasterias glacialis
KW - Mediterranean Sea.
KW - Ophidiaster ophidianus
KW - size
KW - starfish
KW - Coscinasterias tenuispina
KW - Marthasterias glacialis
KW - Mediterranean Sea.
KW - Ophidiaster ophidianus
KW - size
KW - starfish
UR - http://hdl.handle.net/10447/103544
M3 - Article
VL - 31
SP - 73
EP - 82
JO - Thalassas
JF - Thalassas
SN - 0212-5919
ER -