AB 13:275-284 (2011)  -  DOI: https://doi.org/10.3354/ab00373

ABSTRACT: This paper presents the first published data on age, growth and reproduction of the moray eel Muraena helena in the Mediterranean Sea. A total of 193 individuals of M. helena were sampled by longlines at depths from 5 to 80 m in the southern Adriatic Sea. The length and weight of individuals ranged from 27.5 to 121.0 cm and from 116.1 to 3680.0 g, respectively. Age readings from annual zones of M. helena otoliths revealed the presence of age groups 2 to 12. The von Bertalanffy growth function (VBGF) for the sampled population had the following parameters: L_∞ = 162.70 cm, k = 0.089 yr^–1 and t₀ = −0.660 yr. Females dominated the total male:female ratio (0.35:1.00) and, together with immatures, were more frequent in shallow coastal waters. The greatest increase in gonadosomatic index occurred in summer, while condition factor was the ­lowest in winter. The ovaries of moray eels mostly contained oocytes in a pre-vitellogenic or vitellogenic stage and males with testes at maturation stage were observed at the beginning of July. The absence of males and ripe or spent females in the inshore coastal waters suggests that moray eels leave this region in summer to spawn, most likely in the south Adriatic Pit at a depth below 600 m.

KEY WORDS: Moray eel · Muraena helena · Age · Growth · Reproduction · Adriatic Sea