5 research outputs found
Reproduction and recruitment of white mullet (Mugil curema) to a tropical lagoon (Margarita Island, Venezuela) as revealed by otolith microstructure
The reproductive activity and recruitment of white mullet (Mugil curema) was determined by observations of gonad development and coastal juvenile abundance from March 1992 to July 1993. Adults were collected from commercial catches at three sites in northeastern Venezuelan waters. Spawning time was determined from the observation of macroscopic gonadal stages. Coastal recruitment was determined from fish samples collected biweekly by seining in La Restinga Lagoon, Margarita Island, Venezuela. The examination of daily growth rings on the otoliths of coastal recruits was used to determine their birth date and estimate the period of successful spawning. Fish with mature gonads were present throughout the year but were less frequent between September and January when spawning individuals migrated offshore. In both years, juvenile recruitment to the lagoon was highest between March and June when high densities of 25–35 mm juveniles were observed. Back-calculated hatching-date frequency distributions revealed maximum levels of successful spawning in December–January that were significantly correlated with periods of enhanced upwelling. The relation between the timing of successful spawning and the intensity of coastal recruitment in white mullet was likely due to variations in food availability for first-feeding larvae as well as to variations in the duration of the transport of larvae shoreward as a result of varying current conditions associated with upwelling
Is otolith microchemistry (Sr: Ca and Ba:Ca ratios) useful to identify Mugil curema populations in the southeastern Caribbean Sea?
Age, growth and fecundity of the silver mullet, Mugil curema (Pisces: Mugilidae), in coastal arcas of Northeastern Venezuela
We studied fecundity and growth in populations of the silver mullet, Mugilcurema, in coastal areas of northeastern Venezuela between March 1992 and July 1993. The average number of oocytes in gonads of 23-42 cm adults was 54 x 104, and lhe relative fecundity was ! 311 oocytes g-I of fish. The size of mature oocytes did not vary in different portions of the same gonad (p > 0.05) or among the adults in three populations studied. The average egg diameter for adults was 426 ¡lm (CI=4.34). Age of juveniles, colIected from the La Restinga Lagoon at about monthly intervals, from counts of growth lines on the otoliths ranged from 50 to 240 days. The relation of age (number of growth lines) to standard length follows an exponential growth curve. The growth ofjuveniles varied seasonally and was greatest during the rain y season C April to August), when temperatures were highes!. The time of spawning has probably been adapted so Ihat peak recruitment into the lagoons occurs just prior lo the rainy season when conditions for growth are most favorable.We studied fecundity and growth in populations of the silver mullet, Mugilcurema, in coastal areas of northeastern Venezuela between March 1992 and July 1993. The average number of oocytes in gonads of 23-42 cm adults was 54 x 104, and lhe relative fecundity was ! 311 oocytes g-I of fish. The size of mature oocytes did not vary in different portions of the same gonad (p > 0.05) or among the adults in three populations studied. The average egg diameter for adults was 426 ¡lm (CI=4.34). Age of juveniles, colIected from the La Restinga Lagoon at about monthly intervals, from counts of growth lines on the otoliths ranged from 50 to 240 days. The relation of age (number of growth lines) to standard length follows an exponential growth curve. The growth ofjuveniles varied seasonally and was greatest during the rain y season C April to August), when temperatures were highes!. The time of spawning has probably been adapted so Ihat peak recruitment into the lagoons occurs just prior lo the rainy season when conditions for growth are most favorable
Age, growth and fecundity of the silver mullet, Mugil curema (Pisces: Mugilidae), in coastal areas of Northeastern Venezuela
We studied the fecundity and growth in populations of the silver mullet, Mugil curema, in coastal areas of northeastern Venezuela between March 1992 and July 1993. The average number of ovocytes in gonads of 23-42 cm adults was 54 x 104, and the relative fecundity was 1311 ovocytes g-1 of fish. The size of mature ovocytes did not vary in different portions of the same gonad (p 0.05) or among the adults in three populations studied. The average egg diameter for adults was 426 µm (CI= 4.34). Age of juveniles, collected from the La Restinga Lagoon at about monthly intervals, from counts of growth lines on the otoliths ranged from 50 to 240 days. The relation of age (number of growth lines) to standard length follows an exponential growth curve. The growth of juveniles varied seasonally and was greatest during the rainy season (April to August), when temperatures were highest. The time of spawning has probably been adapted so that peak recruitment into the lagoons occurs just prior to the rainy season when conditions for growth are most favorable
<title language="spa">Age, growth and fecundity of the silver mullet, Mugil curema (Pisces: Mugilidae), in coastal areas of Northeastern Venezuela
We studied the fecundity and growth in populations of the silver mullet, Mugil curema, in coastal areas of northeastern Venezuela between March 1992 and July 1993. The average number of ovocytes in gonads of 23-42 cm adults was 54 x 104, and the relative fecundity was 1311 ovocytes g-1 of fish. The size of mature ovocytes did not vary in different portions of the same gonad (p 0.05) or among the adults in three populations studied. The average egg diameter for adults was 426 µm (CI= 4.34). Age of juveniles, collected from the La Restinga Lagoon at about monthly intervals, from counts of growth lines on the otoliths ranged from 50 to 240 days. The relation of age (number of growth lines) to standard length follows an exponential growth curve. The growth of juveniles varied seasonally and was greatest during the rainy season (April to August), when temperatures were highest. The time of spawning has probably been adapted so that peak recruitment into the lagoons occurs just prior to the rainy season when conditions for growth are most favorable