Breeding of Penaeus monodon Fabricius in laboratory recirculation systems

From March to May 1978 over 2 million nauplii were hatched from 34 batches of eggs obtained from five Penaeus monodon females. Females of 50–63 mm carapace length, with one eyestalk removed, spawned viable eggs repeatedly within intermoult periods of 20–30 days indicating that one impregnation was sufficient to fertilize several batches of eggs spawned within one intermoult period. A fresh impregnation was necessary after each moult. The number of eggs per batch varied from 19 000 to 460 000 (mean 217 635) and did not decrease with successive batches. The mean hatch-rate was 30.5% and the mean number of nauplii per brood was 66 000. There was a tendency to a lower hatchrate for batches of eggs produced towards the end of an intermoult period. Samples of larvae from 15 broods were cultured to the post-larval stage at densities of 40–250 larvae/l. Mean survival in 3-1 cultures was 79% but was <13% in larger-scale trials.     

Floating hatchery and net cage culture of Penaeus indicus in the Straits of Johore,Singapore

A simple floating hatchery system with partially submerged tanks (bags made of flexible, plastic-coated fabric) was used to rear the larvae of Penaeus indicus. A total of 1.96 million active nauplii were reared in 6000-l tanks at average densities of 67 nauplii and 42 nauplii/l of tank capacity. Development time from spawning to metamorphosis was 9 days and the average survival rate of nauplii to age PL6 was 49%. From age PL6, post-larvae were reared in nursery net cages (6 × 3 × 0.6 m) in the sea. At densities of 50 000–60 000 post-larvae/cage, the average survival rate from age PL6 to age PL20–22 was 78%; from age PL20–22 to age PL37–44 at densities of 25 000/cage it was 83%.One batch of juveniles was stocked in a prawn pond at age PL27 and another was stocked at high densities in two sizes of net cages at age PL37–50. The prawns grown in the pond reached a mean size of 9 g after 76 days (at age PL103). In large net cages (5 × 5 × 2.5 m) stocked at a density of 80/m², prawns reached a marketable size of 9.8 g after 113 days (at age PL157) with an average survival rate of 32%.Based on these results, the costs of producing post-larvae and juveniles using the floating hatchery and nursery net cage system and of producing live prawns of marketable size by net cage culture were calculated. Modifications in the net cage culture techniques employed are recommended to improve growth and survival rates and reduce production costs.     

Reproductive Performance of Macrobrachium rosenbergii Females in Captivity

Abstract.— The breeding frequency, fecundity, egg hatchability, larval output and viability of pond-reared, mature Macrobrachium rosenbergii females were individually followed up during 180 d. Sexually mature prawns were maintained under controlled laboratory conditions (28.7 C and 12-h light/d) in a 190-L freshwater recirculation system and fed a formulated diet. Ovarian development, moulting and spawning events were checked daily. At least six consecutive moults were recorded for each of the 18 females. The duration of the intermoult period averaged 27.5 d and was not affected by ovarian development or spawning, but intermoult periods followed by spawning had significantly lower growth rates. From a total of 126 moulting events recorded, egg laying successfully followed 76 (60.3%) of them. The number of eggs per spawn (NES) varied from 26,587 to 74,775 for females weighing 20.0 to 55.8 g. The relationship between NES and female size (W; in g) was found to be NES = 484 + 1454W ( r ²= 0.74). Results suggest that the number of viable larvae produced per egg clutch may be increased by in vitro incubation, as the losses of eggs, which usually occur under in vivo incubation, are prevented. The present study illustrates that under adequate and stable rearing conditions, M. rosenbergii females are able to spawn up to five times during 180 d, in comparison to three to five times per year as reported for wild prawn populations.     

Culture of Macrobrachium rosenbergii (De Man 1879) in experimental cages in a freshwater eutrophic lake at different stocking densities

Macrobrachium rosenbergii (de Man 1879) juveniles (0.4 g) were cultured in experimental cages (L × W × H: 2.5 × 1 × 1 m) in Laguna de Bay, the largest lake in the Philippines. The following stocking densities at four replicates each were used: 15, 30, 60 and 90 prawns m⁻² of cage bottom. The mean sizes at harvest after 5 months of culture ranged from 14.3 g for the highest stocking density to 26.3 g for the lowest. The mean size at harvest, daily growth rate and size class distribution were significantly influenced by stocking density, with those at the lowest stocking density showing significantly better growth and overall proportion of larger prawns. Heterogeneous individual growth (HIG) was fairly evident in all treatments. The percentage of blue‐clawed males was not influenced by treatment but the mean weight was significantly higher in the lower stocking densities. Both the percentage and mean weight of berried females were significantly higher in the lowest stocking density. Survival was the highest in the lower stocking densities (55.3%, 54.0%, 52.7% and 36.9% for 15, 30, 60 and 90 prawns m⁻² respectively). Feed conversion ratio (FCR) improved with decreasing stocking density, ranging from 2.1 to 3. As expected, yield per cropping increased with stocking density and ranged from 450 to 1089 g m⁻² yr⁻¹ of actual cage area. Production values obtained in the cage cultured M. rosenbergii were comparable to or even higher than those reported from pond culture, given that the stocking densities used in this study were generally higher than in ponds. The results show that the farming of M. rosenbergii in cages in lakes is a viable alternative to pond culture and has the potential of improve aquaculture production in lakeshore fish farming communities.     

The effect of male absence on the larval production of the spider crab Maja brachydactyla Balss, 1922

The spider crab Maja brachydactyla, Balss 1922 can produce three consecutive broods per breeding season in the wild, whereas females in captivity can spawn up to four times in the absence of males. The effect of male absence on the larval production of the spider crab M. brachydactyla was studied in a 2‐year experiment in which females were kept in captivity in the presence or absence of males. The broodstock were maintained under natural photoperiod conditions, temperature (18.5 ± 1.0°C) and salinity (34.8 ± 0.7 g L^?1). The number of larvae, and when possible, the dry weight and proximate biochemical composition of each larval batch were calculated and the data grouped seasonally. The larval production (P < 0.001) and protein content (P = 0.037) were significantly lower in the absence of males. However, considering that the larval production in male presence decreased due to the low female survival rate, particularly in the last part of the experiment, the presence of males should be managed to maintain a high larval production and condition without jeopardizing the survival of females. Therefore, we recommend keeping females segregated from males and transferring males to female tanks only to mate.     

All-male broods of Tilapia nilotica × T. aurea hybrids

The proportion of males in single pair crosses between Tilapia nilotica females and T. aurea males was found to vary between 50 and 100%. There was no apparent influence of the T. aurea males on these proportions. In a similar test nine T. vulcani females were paired with T. aurea males, and the proportion of males in their hybrid offspring ranged between 93 and 98%. Two T. nilotica mothers of all-male hybrid broods mated with unselected T. nilotica males, and all their daughters also reproduced all-male hybrid broods when crossed with T. aurea males. The reciprocal cross of T. aurea females with T. nilotica males reproduced three males to each female offspring. Growth rate tests of the all-male T. nilotica × T. aurea hybrids, and the T. vulcani × T. aurea hybrids did not reveal heterosis.     

The effect of size-grading juvenile Macrobrachium rosenbergii prior to stocking on their population structure and production in polyculture: II. Dividing the population into three fractions

Juvenile prawns (ca. 1.1 g) were size-graded into upper (32%), middle (45%) and lower fractions (23%). The graded fractions and the graded and recombined control were stocked into 400-m² earthen ponds, at a density of 2/m². The prawns were grown for 97 days in polyculture with tilapia, common carp, silver carp and grass carp. The proportion of females was higher than that of males in all of the groups except the lower fraction in which males predominated. The fractions differed in the proportions of the male and female morphotypes. The upper fraction had a low proportion (8%) of small males (SM) and a high proportion (22%) of blue claw males (BC). The lower fraction showed the reverse trend, with a high proportion (50%) of SM and a low proportion (3%) of BC. The middle fraction was intermediate and similar to the control. The proportions of mature females in the upper and lower fractions were 63 and 6% respectively. The middle fraction was intermediate (21%) but lower than the control group (45%). Survival in the grow-out phase was ca. 88% in all the groups. The three graded groups differed significantly in mean weight, with the largest prawns occurring in the upper fraction. Since the price of prawns is size-dependent, the net income from the upper fraction was almost nine times that of the lower fraction. The weighted mean income from the three fractions did not differ from that of the control. The large differences in yield and net income among the graded fractions, as well as the lack of increase in the net income compared with the control, are explained by early male morphotype determination.     

The fertility of the Port Lincoln oyster (Ostrea angasi Sowerby) from West Lakes,South Australia

During 1977–1978 the spawning season of the Port Lincoln oyster (Ostrea angasi Sowerby) extended from about mid-October to early March. Between 5.6% and 21.4% of randomly sampled adult oysters (larger than 68 mm in length) were incubating larvae and between 0.91 and 1.33 broods of larvae were produced per adult oyster. Large oysters (68–94 mm in length) had a mean of 12.1 × 10⁵ larvae per brood. The incubation period under natural and laboratory conditions ranged from 15–22 days and there are similarities in the breeding biology of O. angasi, the European oyster (Ostrea edulis L.) and the Olympia oyster (Ostrea lurida Carpenter).     

Effects of different feeding regimes on ovarian maturation and spawning of pond-reared giant tiger prawn in Thailand

Large pond-reared Penaeus monodon were used in three maturation and spawning trials lasting 60 days. One group of prawns was fed a fresh diet only; a second group was supplied a fresh diet combined with a formulated pelleted diet; a third group of prawns received the formulated diet only. Total maturation (N = 66 and 55) and spawning events (N = 63 and 48) were much greater for prawns receiving only the fresh diet, and the combined fresh with formulated diets, respectively. Prawns receiving only the formulated diet matured only 12 times, and spawned 11 times. Prawns fed a fresh diet produced significantly more eggs than those given a formulated diet alone. No significant differences were seen in eggs produced per spawning event, % fertilization, % hatch or % metamorphosis from egg to protozoea. Female prawns exhibited greater mortality than did males, while females on the fresh diet only had greater mortality than did other females, presumably due to greater handling and other stress factors. Female prawns on a combined diet had lower mortality than other females. The formulated diet used is suitable for supplementation, but not as a sole maturation food.     

Individual growth pattern of juvenile stages of the Chinese mitten crab (<Emphasis Type="Italic">Eriocheir sinensis</Emphasis>) reared under laboratory conditions

The specific growth pattern of Chinese mitten crab, Eriocheir sinensis, during the juvenile stages was investigated under an individual rearing system for 160 days, including parent crab selection, hatchery management, larval stages, and juvenile cultivation. There were 36 males and 40 females developed from megalopa to the juvenile crab stage 10 (M–C10), with a total survival of 38%. The survival rate in early stages (M–C3) remained less than 80%, which was lower than that in latter stages (>?90%). The intermoult duration sharply increased in an exponential manner (y?=?3.1059e^0.2149x R²?=?0.9383) from 4?±?0.54 days to 38?±?6.26 days. The increments in wet weight, carapace width, and carapace length per moult were recorded throughout the experiment, which followed certain patterns with progressing moulting time. In addition, moulting increment in wet weight varied greatly from C1 to C6, with a minimum increment of 108.09%. Meanwhile, the specific growth rate markedly increased in the early stages and subsequently decreased, mainly because of significant increases in the intermoult duration starting from C6 stage. Males and females could be differentiated at C4 based on sexual dimorphism in the abdomen, and the most distinct changes in female and male juvenile crabs occurred in the shape of the abdomen and amount of cheliped fluff, respectively.     

Postlarval growth of the freshwater prawn, Macro-brachium australiense Holthuis, 1950 (Crustacea: Decapoda: Palaemonidae)

Growth of newly metamorphosed Macrobrachium australiense was monitored in individually vidually held and group held laboratory animals over 28 weeks. A breeding population was also established in a farm dam and the growth of young juvenile F₁ progeny was recorded for a similar time. Up to 26 moults were recorded in this period and intermoult periods increased with age. Prawns held in groups grew better than those held individually. Reproductive maturity was attained by some females in group held laboratory and farm dam animals within the observation period. Length—weight regression equations were calculated for laboratory maintained prawns, i.e., log W = 0.44+ 2.44 log L; log W = 0.45 + 2.46 log L for individually held males and females, respectively; log W = 0.27 + 2.70 log L for group held males and females.     

Observations on growth, sexual maturity and spawning performance of pond-reared Penaeus merguiensis

This 12‐month preliminary study investigated the development of sexual characters, primary sexual maturity, ovarian maturity and spawning performance of pond‐reared Penaeus merguiensis in relation to culture conditions in south‐east Queensland, Australia. Post‐larvae of P. merguiensis were produced and cultured in two 60‐m³ tanks during the first 14 weeks. Before winter, they were harvested and stocked in three different overwintering facilities: a 200‐m² covered pond, two 60‐m³ outdoor tanks and a 15‐m³ indoor, recirculated tank at a stocking density of 10 individuals m^?2. The development of sexual characters was found to be similar to that reported previously in wild P. merguiensis. Males matured at younger ages and smaller sizes than females. Overall, the average size at primary sexual maturity of pond‐reared P. merguiensis was 23.1 mm carapace length for males (possessed spermatophores) and 29.3 mm for females (being impregnated). Water temperature and the availability of natural food strongly influenced prawn growth, maturity rate and their subsequent spawning performance. Growth, maturity rate and spawning performance of prawns in the covered pond were significantly higher than in the other overwintering facilities. Prawns started mating at 6–7 months, reached full ovarian maturation and spawned as early as about 8 (peaked at 9–11) months from hatching, producing high fecundity and viable larvae. There was a strong relationship (P < 0.001) between prawn size and fecundity. The results of this study suggest a potential for using pond‐reared broodstock P. merguiensis for hatchery production and for domestication or selective breeding programmes.     

Yield characteristics and morphometric relationships of giant freshwater prawn,Macrobrachium rosenbergii (de Man, 1879)

Meat yield of 233 individuals of giant freshwater prawn, Macrobrachium rosenbergii (de Man, 1879), and their morphometric relationships were examined. Morphometric parameters of different length and weight measurements were recorded for both the sexes separately and subjected to analysis. The meat yield of prawns was size and sex dependent with females showing significantly greater (P < 0.05) tail meat yield than males. The tail meat as a body weight percentage ranges from 26.12 to 40.75 and 32.97 to 42.11 in males and females, respectively. Much of the differences in yield are related to the size and weight of the head and claws. The head weight of males was observed to be higher compared to females in all the size classes. Regression slopes of total length versus body weight and total length versus head weight were significantly higher than critical isometric value indicating high positive allometric growth in both the sexes, with males showing significantly higher (P < 0.05) slope than females. The relationship parameters of total length versus tail weight and total length versus tail meat showed a positive allometric growth in females, whereas it is isometry and negative allometry in males. The morphometric relationship of tail length versus all weight measurements showed positive allometry and negative allometry in females and males, respectively.     

The effect of density of Macrobrachium rosenbergii raised in earthen ponds on their population structure and weight distribution

The population structure and weight distribution of Macrobrachium rosenbergii raised in earthen ponds in polyculture with fish were studied. Over 10 000 prawns were grown in 12 ponds stocked with 1, 2, 3 or 4 prawns per m². Females were more abundant than males in all of the treatments. The proportions of three different male morphotypes, blue claw, orange claw and small males, changed with density but those of the female morphotypes did not. A detailed analysis of prawn weight distribution (mean, coefficient of variation and skewness) was carried out separately for each sex and for the morphotypes within each sex. Prawn survival was approximately 85%, independent of prawn density. Yield increased and mean prawn size decreased with prawn density. The most profitable density was 2 prawns per m². The biological mechanisms controlling variation in sex ratio and morphotype frequency and the social control of growth are discussed.     

Evaluation of the production potential of Macrobrachium rosenbergii (de Man) in monoculture and in polyculture with Nile tilapia and common carp in Saudi Arabia

The feasibility of polyculture of Macrobrachium rosenbergii (de Man) with two fish species, Nile tilapia, Oreochromis niloticus (L.), and common carp, Cyprinus carpio L., was examined and compared with monoculture of M. rosenbergii in 100-m² ponds. Overall percentage of females (56.8%) was higher than that of males (43.2%). The proportions of females, males and their morphotypes did not differ significantly between monoculture and polyculture. After 196 days of culture, the mean harvest weight of prawns in monoculture (30.2 g) was significantly greater than that in polyculture (21.3 g). Yield in monoculture (1152 kg ha^-1) was significantly greater than (1.62 times) that of polyculture (711 kg ha^-1). Total yield from polyculture including yield of tilapia (2544 kg ha^-1) and common carp (2999 kg ha^-1) was almost five times as great as that of prawn monoculture. Survival and food conversion rate of M. rosenbergii did not differ significantly between monoculture and polyculture.     

Progress Toward Year-round Spawning of Southern Flounder Broodstock by Manipulation of Photoperiod and Temperature

Reliable methods have been developed for controlled spawning of captive southern flounder, Paralichthys lethostigma, broodstock during their natural winter (December–February) spawning season. From 1999 to 2004, we evaluated the effects of manipulation of photoperiod and temperature on both advance and delay spawning to produce viable embryos throughout the year. Wild‐caught adult broodstock were held in 4.8‐ to 7.0‐m³ controlled‐environment tanks at a sex ratio of approximately 12 females to 4 males. Broodstock were subjected to different artificial photothermal conditioning regimes: extended winter (EW), accelerated (A‐10‐, A‐6‐, A‐4.5‐, and A‐3.8‐mo regimes), and delayed (D‐16‐ and D‐14‐mo regimes), with gradual and abrupt transitions, respectively, from long to short daylengths. Under an EW cycle, fish were exposed to constant short daylengths (10 L: 14 D) after the winter solstice in January. Eighty‐seven natural spawnings from December to April produced 18.3 × 10⁶ eggs, with 20.9% hatching successfully (i.e., overall egg viability). Under an A‐10‐mo cycle, rate of decrease in daylength was accelerated after the summer solstice in July, to reach winter conditions in October. Seven induced spawning trials from October to November produced 897 × 10³ eggs, with 40.4% viability. Under an A‐6‐mo cycle, rate of change of photoperiod was accelerated after the winter solstice in January, to reach winter conditions in July. Three induced spawning trials in July produced 550 × 10³ eggs, with 14.7% viability. Under an A‐4.5‐mo cycle, broodstock exposed to EW from January through April were exposed to an accelerated cycle to reach winter conditions by October. Four induced spawning trials from September to November produced 729 × 10³ eggs, with 28.7% viability. Under an A‐3.8‐mo cycle, broodstock exposed to EW conditions from January through April were exposed to an accelerated cycle to reach winter conditions by September. Five induced spawning trials from September to November produced 510 × 10³ eggs, with 45.9% viability. Under a D‐16‐mo cycle, fish were exposed to a decelerated decline in photoperiod after the summer solstice in July, to reach winter conditions in May, when atretic females were observed. Under a D‐14‐mo cycle, fish were exposed to constant summer conditions from December through mid‐June and then to an abrupt decline in photoperiod to winter conditions in late June. Six induced spawning trials from September to November produced 763 × 10³ eggs, with 13.0% viability. Production of viable embryos was greatest during the extended winter because of abundant natural spawnings. While successful natural spawnings were rare during the fall or summer, viable embryos were produced through induced spawnings during all seasons of the year, with no significant (P > 0.05) differences in egg viability. Extended winter conditions prolonged spawning from 3 to 5 mo. Accelerated (3.8–10 mo) regimes were effective in producing viable embryos from summer through fall, but a minimum of 5 mo was required to complete gonadal recrudescence. While constant long daylengths after the summer solstice delayed gonadal recrudescence, with spawning obtained 2.5 mo after an abrupt reduction to short daylengths, a decelerated decline in photoperiod did not. Artificial control of daylength enabled precise control of gonadal recrudescence and year‐round spawning in southern flounder without adverse effects on the quality of eggs and larvae and will improve availability of seedstock for commercial aquaculturists.     

Growth, Maturation, Induced Spawning, and Production of the First Generation of South American Catfish, Pseudoplatystoma sp., in North America

Growth, plasma steroids, and the appearance of gonads (histology and gonadosomatic index) were followed in South American catfish (surubim, Pseudoplatystoma sp.) raised in captivity in the aquaculture facility at The Ohio State University, Columbus, Ohio, USA, from 2003 until 2006. Broodstock growth showed a great individual variation and it did not seem sex dependent. The levels of 11‐ketotestosterone were high in males during the reproductive season. Three out of six females spawned after receiving two doses of carp pituitary extract (0.5 and 5 mg/kg) at 11‐h intervals. Fertilization was performed in only one female in February 2006. Egg size was 0.73 ± 0.06 mm in diameter at stripping. Two males released sperm, and it was used for fertilization. Sperm concentrations were 24 × 10⁹ and 15.5 × 10⁹ spermatozoa/mL in Male 1 and Male 2, respectively, and viability was confirmed after activation in 0.3% NaCl. Embryo survival at 9 h after fertilization was 44 and 23% for Male 1 and Male 2, respectively. Embryos hatched 15 h after fertilization. Larvae were 3.53 ± 0.09 mm in length at hatching and were successfully raised (72% survival after 2 wks) using live brine shrimp nauplii.     

Induction of meiotic gynogenesis in the stinging catfish Heteropneustes fossilis (Bloch) and evidence for female homogamety

This study reports the results on induced meiotic diploid gynogenesis and female homogametic nature in the Indian catfish, Heteropneustes fossilis. The eggs of H. fossilis were inseminated with conspecific sperm. The sperm suspension was diluted to 1 × 10⁷ sperm mL⁻¹ in Hanks balanced salt solution. Sperm were irradiated under UV light, with the exposure time ranging from 15 to 360 s (7500 ergs mm⁻² for 60 s). The genetic inactivation of paternal chromosomes was confirmed by chromosome counting from the larval cells and the larvae also had a characteristic haploid syndrome. A typical ‘Hertwig effect’ in the yield of hatched larvae was observed with doses of UV exposure >75 s (9375 ergs mm²). Larvae resulting from sperm UV irradiated above 120 s (15 000 ergs mm²) were 100% haploids. Application of heat shock to the activated eggs was effective in suppressing the release of the second polar body (meiotic gynogenesis) and resulted in diploid gynogenetic larvae morphologically identical to those of the control. The best yield of diploid gynogens (49.3% with respect to the control) was found to be at 6 min after egg activation and the heat shock at 41 °C for a 1-min duration, at an ambient water temperature of 27 °C. A total of 113 diploid gynogenetic fry from seven different female fish were reared and subjected to sexing. All gynogenetic fish were female in contrast to the control, which had a mean sex ratio of 56.7% females (which was not significantly different from 50% female). From these results, the sex determination mechanism in H. fossilis was presumed to be female homogamety.     

Live transportation of Macrobrachium rosenbergii (De Man) in chilled sawdust

Three cooling rates of 1.26±0.09°C h^?1 within 8 h (slow, T₁), 2.52±0.18°C h^?1 within 4 h (moderate, T₂) and 5.04±0.36°C h^?1 within 2 h (fast, T₃) were tested to cold‐anaesthetize farm raised Macrobrachium rosenbergii (De Man) (45–52 g) in each case from 25°C down to 15±1°C in a refrigerated chilling tank, provided with aeration. The cold‐anaesthetized prawns subjected to each chilling rate were packed in an insulated cardboard box (triplicate) between two layers of moist and chilled (2–3°C) sawdust, and kept inside a chilled storage cabinet at 15±1°C, for set durations of 6, 9, 12, 15 and 18 h. Survival was determined by revitalizing the prawns in aerated water with an initial temperature of 20°C, which was raised to 29±1°C within 3 h. The experiment was repeated using berried females acclimated to brackishwater of 12 g L^?1 salinity and the percentage survival recorded after live storage for durations ranging from 6 to 24 h at intervals of 3 h. Statistically valid safe durations for obtaining 100% survival of the cold anaesthetized and live stored prawns were determined using probit analysis at the three chilling rates tested, and were found to be 7.39, 6.98 and 4.54 h in the case of adult prawns, and 7.87, 8.17 and 6.43 h for berried females for T₁, T₂ and T₃ respectively. For practical purposes, the durations that yielded 95% survival rates were computed to be 16.47, 12.14 and 8.35 h in the case of adult prawns and 18.49, 19.02 and 11.11 h for berried females for T₁, T₂, and T₃ respectively. The berried prawns revitalized after live storage were incubated in tanks and the zoea larvae reared up to postlarvae (PL‐5), and compared against a control. No significant difference was found in larval hatch fecundity, survival rate and the production of PL L^?1 between the treatment and control, indicating that the method of cold anaesthetization and live storage of berried prawns could be used for successful transportation of broodstock.     

Age and growth of Gerres sp. (Perciformes: Gerreidae) in Okinawa Island of Southern Japan

A total of 518 Gerres sp. were collected around Okinawa Island, Japan, from November 2002 to July 2005, with monthly sampling where the standard length of females (n=218) were 56.2–147.1 mm, and males (n=149) were 62.2–139.4 mm. The maximum ages observed for females were 5⁺ years and males were 4⁺ years, estimated by transverse sectioned sagittal otoliths. Mean marginal increment indicated that opaque rings were formed once a year during April to July. The standard length (SL; mm) — body wet weight (BW; g) relationships were described as BW=(3.26×10⁻⁵) SL^2.97 and BW=(3.13×10⁻⁵) SL ^2.98 for females and males, respectively, and the standard length at age described by von Bertalanffy growth function for females, L _t=137.1(1−e^{−0.80[t+0.80]}) and males, L _t=127.3(1−e^{−0.82[t+0.93]}).