ABSTRACT
This paper summarises observations on reproductive activity of the feather-stars Lamprometra klunzingeri (Hartlaub), Heterometra savignii (J. Müller), and partly Capillaster multiradiatus (Linnaeus), from the Gulf of Aqaba (Red Sea). During this study gonads of nearly 1000 specimens of the three species were investigated. Along each arm, gonads of the same animal develop asynchronously, those in the lower quarter of the arm maturing first. During the reproductive cycle oogonia and spermatogonia differentiate from the innermost layer of the gonad wall. Six stages were defined in the reproductive cycle of each gonad. During a single reproductive cycle several spawns from each gonad are possible. Maturation of spermatozoa is gradual and liberated ripe sperm masses accumulate in the lumen of the testis. Egg maturation prior to spawning involves only 30% at the most of the oocytes present. Gonads under 50 um in diameter are usually inactive, and those with a diameter over 250 um are well advanced in the reproductive cycle. During reproduction, only 1.2% of female L. klunzingeri and 1.1% of female H. savignii held ripe eggs in the ovarian lumen. Males with ripe sperm masses comprised 25% in L. klunzingeri and 32% in H. savignii.
Reproductive activity of L. klunzingeri is continuous, without a definite seasonal pattern, whereas in H. savignii cessation of maturation occurs between April and June. Gonad structure and gametogenesis of C. multiradiatus resemble those of the other two species. The highest relative frequency of mature individuals was for L. klunzingeri in August (33%), for H. savignii in September (45%) and for C. multiradiatus in December (38%).
