Journal of the Marine Biological Association of the United Kingdom

Research Article

Determination of Growth and Age of Slow Growing Brittle Stars (Echinodermata: Ophiuroidea) From Natural Growth Bands

Corinna Dahma1 and Thomas Breya1

a1 Alfred Wegener Institute for Polar and Marine Research, PO 120161, D-27515 Bremerhaven, Germany. E-mail: [email protected]

Growth in ophiuroids is highly variable, and with increasing size and age of an ophiuroid specimen more and more of the innermost growth rings on the vertebral ossicles become overgrown and hence invisible. Two approaches to estimate individual age of slow growing brittle stars using the high Antarctic species Ophionotus victoriae are compared. One method interprets natural growth ring readings as size-increment data, whereas the second method compensates for growth ring overgrowth by means of an iterative corrective approach. Preconditions as well as advantages and disadvantages of both methods are discussed.