Reproductive cycle and size at first sexual maturity ofHexaplex trunculus(Gastropoda: Muricidae) in the Gulf of Gabès (southern Tunisia)

Age, growth and reproductive parameters were estimated for Raja radula from the Gulf of Gabes (southern Tunisia, central Mediterranean Sea), collected monthly during 2007 from commercial fisheries. In total, 550 females (18.5–80.0 cm TL) and 400 males (13.4–65 cm TL) were examined to study the reproductive cycle. A subsample of 272 specimens (140 females and 132 males, ranging from 15.5 to 80 cm in total length, TL) was used for age and growth estimation derived from vertebral centra. The marginal-increment and edge analysis showed annual deposition of growth bands. The oldest female in the study was 12 years old and 80 cm in TL, whereas the oldest male was 9 years old and 65 cm in TL. The von Bertalanffy growth parameters were L∞ = 76.36 cm, K = 0.22 year–1 and t0 = –0.16 years for males. There was no significant difference in growth between the sexes. The size-at-maturity was 47.05 cm for males and 56.48 cm for females. The age-at-maturity was estimated to be 4.47 and 5.89 years, respectively, for males and females. There was no significant difference of size- and age-at-maturity between the sexes. Females carrying egg cases occurred throughout the year. Variations in the gonadosomatic and hepatosomatic indices showed a continuous reproductive cycle throughout the year.

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Annual reproductive cycle, spawning periodicity and sexual maturity of false scad Caranx rhonchus (Geoffroy Saint-Hilaire, 1817) (Pisces, Carangidae) from the South-Eastern Mediterranean (Gulf of Gabès, Tunisia)

Journal of Applied Ichthyology ◽

10.1111/jai.12675 ◽

2015 ◽

Vol 31 (3) ◽

pp. 437-441 ◽

Cited By ~ 1

Author(s):

A. Sley ◽

A. Hadj Taeib ◽

O. Jarboui ◽

M. Ghorbel ◽

A. Bouain

Keyword(s):

Reproductive Cycle ◽

Sexual Maturity ◽

Eastern Mediterranean ◽

Annual Reproductive Cycle ◽

The South ◽

Gulf Of Gabes ◽

South Eastern ◽

Gulf Of Gabès ◽

Spawning Periodicity

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Reproductive cycle of Bolinus brandaris (Gastropoda: Muricidae) in the Gulf of Gabès (southern Tunisia)

Mediterranean Marine Science ◽

10.12681/mms.325 ◽

2013 ◽

Vol 14 (1) ◽

pp. 24 ◽

Cited By ~ 7

Author(s):

K. ELHASNI ◽

P. VASCONCELOS ◽

M. GHORBEL ◽

O. JARBOUI

Keyword(s):

Reproductive Cycle ◽

Sexual Maturity ◽

Fishery Management ◽

Gonadosomatic Index ◽

Condition Index ◽

Spawning Season ◽

Gonad Maturation ◽

Gulf Of Gabes ◽

Gulf Of Gabès ◽

Bolinus Brandaris

The reproductive cycle of the purple dye murex (Bolinus brandaris) from the Gulf of Gabès was studied through gonad histology and calculation of bio-physiological indices (general condition index - K and gonadosomatic index - GSI). The shell length at first sexual maturity (SL50) of B. brandaris was also investigated using a macroscopic maturation scale. The population sex ratio was statistically unbalanced (M:F = 1:1.5), with a significant dominance of females. Monthly variation in gonad maturation stages, K and GSI revealed that B. brandaris has an annual reproductive cycle, long period of gonadal activity and slight asynchrony between sexes. The spawning season extended between April and July, with a clear spawning peak from May to June. The SL50 was reached at 56.4 mm in females and 54.6 mm in males. At present, B. brandaris has no commercial value in Tunisia, but it is predictable that it will become a fishery-exploited species in the near future. The present data, particularly the timing of spawning season and the size at first sexual maturity, constitute baseline information for the proposal of fishery management measures, aiming to ensure sustainable exploitation and long-term preservation of this alternative fishing resource.

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New data on the reproductive biology of the common guitarfish of the Gulf of Gabès (southern Tunisia, central Mediterranean)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315408001550 ◽

2008 ◽

Vol 88 (5) ◽

pp. 1063-1068 ◽

Cited By ~ 9

Author(s):

Samira Enajjar ◽

Mohamed Nejmeddine Bradai ◽

Abderrahmen Bouain

Keyword(s):

Sexual Maturity ◽

Gravid Female ◽

Central Mediterranean ◽

Gulf Of Gabes ◽

Chemical Balance ◽

Gulf Of Gabès ◽

Southern Tunisia ◽

The Common ◽

Males And Females ◽

Size At Birth

The common guitarfish Rhinobatos rhinobatos is abundanly captured along the coast of the Gulf of Gabès (southern Tunisia). The sizes at the first sexual maturity of females and males are 790 and 700 mm total length (TL) respectively. Females are larger than males; the maximum TL for males and females is 1000 and 1200 mm respectively. The smallest gravid female observed is 750 mm TL. Rhinobatos rhinobatos is an aplacental viviparous species. The two ovaries and the two uteri are functional. Mature oocytes and foetuses are symmetrically distributed respectively in ovaries and uteri. Vitellogenesis and gestation occur simultaneously. Gestation lasts 10 to 12 months; parturition occurs from the end of summer to the beginning of autumn. Mating and ovulation take place after parturition. Ovarian fecundity is higher than uterine fecundity; means of 8.95 and 5.34 young per year are respectively calculated. There is a positive relationship between the two categories of fecundity and size of females. The size at birth ranges from 250 to 290 mm TL. The common guitarfish is purely a lecithotrophic species. The chemical balance of development is estimated at 1.02.

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