Biological and Fisheries Aspects of Black Tiger Shrimp (Penaeus monodon Fabricius, 1798) in East Aceh Waters, Indonesia

Penaeus monodon (tiger shrimp), Metapenaeus monoceros (brown shrimp), and Fenneropenaeus indicus (white shrimp) are the most economically important shrimp species in the waters of the Bay of Bengal, Bangladesh. This is the first analytical study to assess three major shrimp stocks using both length-based and catch-based methods, such as length-based Bayesian biomass estimation (LBB), length-based indicator (LBI), and a catch-based method entitled JABBA (Just Another Bayesian Biomass Assessment), to explore and process the data; estimate the growth parameters, with length at first capture; present relative biomasses; and approximate the reference points. The parameters of the von Bertalanffy Growth Function (VBGF) analysis for the tiger, brown, and white shrimps were L∞ = 113.0 mm, 85.4 mm, and 76.4 mm, respectively, for carapace length. Our results showed that the relative biomass level (B/BMSY) of the tiger shrimp was 0.43, suggesting an overfished status, and brown and white shrimps were 0.84 and 0.96, indicating that they were fully exploited but not overfished. This study, therefore, advised an optimum carapace length limit to catch from 57.0–70.0 mm for tiger shrimp, 44.0–53.0 mm for brown shrimp, and 40.0–48.0 mm for white shrimp. The estimated maximum sustainable yield (MSY) reference points were as follows: optimal biomass BMSY = 3116 mt, 15,885 mt, and 2649 mt for tiger, brown, and white shrimp, respectively, and optimal harvest rate uMSY = 12%, 33%, and 8% for tiger, brown, and white shrimp, respectively. The average annual catch values for the last ten years were 265 mt, 2396 mt, and 115 mt below the estimated MSY values of 389 mt, 4899 mt, and 209 mt for tiger, brown, and white shrimp, respectively. But, brown shrimp had the estimated highest carrying capacity (31,770 mt) and intrinsic growth rate (0.66) than the tiger and white shrimp, which was replicated distinctly in the graphical representation of the Kobe plot and the surplus production plot. Hence, the brown shrimp stock is estimated to be in a better state than the tiger and white shrimp stocks.

Populations of the green spiny lobster Panulirus gracilis (Streets 1871) have sustained increasing harvesting pressure in Pacific Panama for decades, but basic information about their biology and ecology in the region is scarce. This study provides baseline data for the densities and biometrics of P. gracilis in Las Perlas and Coiba Archipelagos. The number of surveyed lobsters in both archipelagos was surprisingly low (85 in Las Perlas and 67 in Coiba), and average densities were dismal (4.1 ± 8.8 ind. ha−1 and 5.3 ± 7.6 ind. ha−1, respectively). Saboga and San Jose Islands had the highest relative densities of P. gracilis in Las Perlas, whereas intermediate relative densities were found only on Coiba Island in the Coiba Archipelago. Lobster density was not associated with either substrate or depth. In Las Perlas, female carapace length (CL) was 40–95 mm and that of males was 25–100 mm; in Coiba, female CL was 45–124 mm and male CL was 45–121 mm. In Las Perlas, the smallest lobster with eggs had a CL = 65 mm and a tail length (TL) = 120 mm, whereas the smallest in Coiba had a CL = 60 mm and a TL = 81–115 mm. We recommend implementing: (1) the minimum capture CL as the average carapace length at which half of the lobster population from Coiba is adult (CL = 84 mm; TL = 112–155 mm); (2) a fishing season no longer than 6 mo; (3) management decisions involving local fishermen and native peoples; (4) marine reserves or no-take areas (NTA); and (5) long-term monitoring plans, as the best current options to insure the survival of P. gracilis in the region.

The reproductive biology of Portunus sanguinolentus (Three Spot Swimming Crab) wasinvestigated in the coastal waters off Negombo, Sri Lanka from February 2014 to January2015. Reproductive activity was assessed using macroscopic and microscopic observations ofgonad characteristics, trends of gonad indices, size at first sexual maturity and differences inthe monthly sex ratio. Though P. sanguinolentus females have higher body weight thanmales, carapace length, carapace width or body weight of males and females were notsignificantly different (Mann-Whitney test, p>0.05). Ovigerous females were observedthroughout the year, confirming that they are continuous spawners however, peak spawningwas in October. Percentage Gonadosomatic Index (GSI) of females is significantly higherthan the males (t-test; p<0.05; df=193) and GSI values ranged from 0.02 to 3.69 in males and0.12 to 9.44 in females. Sex ratio of P. sanguinolentus population fluctuated seasonally andsignificantly high male to female sex ratio was observed in October 2014 (χ2 test). Size atfirst sexual maturity (Lm50) was estimated at 9.75 and 8.90 cm (carapace width, CW) formales and females, respectively. Three types of external egg masses; stage I, II and III wereidentified based on colour and size of the berried eggs. The mean diameter (μm) of eggs ineach stage was reported as 253.8±3.19, 281.8±6.79, 316.5±9.78, respectively. The averagefecundity of P. sanguinolentus varied from 2.04×104 to 1.24×106 and it increased withincreasing CW. Present study proposes a new method to identify mature and immature malesby using their external characteristics. Accordingly, in mature males, blue color patches canbe observed on the ventral side of chelar propodus and merus but this colour pattern is notprominent in immature males and absent in mature females.Keywords: Portunus sanguinolentus, Sri Lanka, Chelar propodus, Merus, Size at first sexualmaturity

The influence of seagrass type on the distribution and abundance of postlarval and juvenile tiger prawns ( Penaeus esculentus and P. semisulcatus) in the western Gulf of Carpentaria, Australia

The purpose of this study was to examine the effect of environmental variables by combining information about the immigration of juveniles during one year. The study of population structure, growth, and morphometric relationships of Penaeus monodon Fabricius in 1798 was carried out in four zones of the Segara Anakan Lagoon (SAL(Zone I (mesotrophic/in two main rivers Cibereum and Citanduy): Zone II (eutroph/in the northeastern part of the lagoon): Zone III(eutroph/in the south-eastern part of the lagoon): Zone IV (mesotrophic/near the western channel) for one year (December 2016 - January 2017). The average carapace length (CL) during the rainy season was 36.35 mm in October and 28.61 mm in December, reflecting changes in shrimp size in the population. The morphological relationship, in terms of total length (TL, mm) and carapace length (CL, mm) of male and female shrimps were significantly correlated with TL = 15,825 + 3,225 CL (r = 0,960) and TL = 25,462 + 2,897 CL (r = 0,978), each. The allometric equations for carapace length (CL mm) and weight (W, g) are Wmale = 10-3 2.834 CL2.528, and Wfemale = 10-3 1.520 CL2, The local distribution of the shrimps suggested that the SAL represent an important nursery ground in its life history.

A laboratory-based study was made of the responses of juveniles (8 to 24 mm carapace length) and adults (over 24 mm CL) of brown (Penaeus esculentus) and grooved (P. semisulcatus) tiger prawns to two habitats: simulated seagrass and bare sand. At night, the brown tiger prawns spent about 80% of their nonswimming time in seagrass, whereas the grooved tiger prawns spent equal amounts of time in both habitats. In daylight (0830 to 0930 hours), the brown tiger prawns were found mainly in the seagrass, with most of those larger than 15 mm CL buried in the substrate whereas smaller individuals were divided equally between standing on the bottom, burying in the sand, or clinging to the seagrass, mainly to the upper half of the fronds. Grooved tiger prawns between 15 and 25 mm CL were also found mainly in seagrass in the morning, but both smaller and larger animals were found equally in both habitats. Most grooved tiger prawns found in seagrass during the day were buried; few were clinging to the seagrass or standing on the substrate. The results show that both species of tiger prawns show preferences with respect to structures in their environment and that these preferences are influenced by the size of the animals.

Presence of tiger shrimp Penaeus monodon Fabricius, 1798 (Penaeidae) in the Egyptian commercial shrimp catch, Alexandria, Egypt

The population dynamics of small tiger prawns (Penaeus esculentus and P. semisulcatus) were studied at three sites around north-western Groote Eylandt, Gulf of Carpentaria, Australia, between August 1983 and August 1984. Seagrasses typical of open-coastline, reef-flat and river-mouth communities were found in the shallow depths (≤2.5 m) at these sites. The temperature and salinity of the bottom waters did not differ among the shallowest depths of the three sites and mean values at night ranged from 21.9 to 32.0 °C, and from 30.1 to 37.5% S. Data from fortnightly sampling with beam trawls showed that virtually all post-larvae (∼90%) were caught in the intertidal and shallow subtidal waters (≥2.0 m deep). At one site, where the relationship between seagrass biomass, catches and depth could be studied in detail, high catches were confined to seagrass in shallow water, within 200 m of the high-water mark. This was despite the fact that seagrass beds of high biomass (>100 g m-2 between August and February) were found nearby, in only slightly deeper water (2.5 m). It is likely, therefore, that only the seagrass beds in shallow waters of the Gulf of Carpentaria act as important settlement and nursery areas for tiger prawns. In general, catches of tiger prawn postlarvae (both P. esculentus and P. semisulcatus) and juvenile P. esculentus on the seagrass in the shallowest waters at each site were higher in the tropical prewet (October–December) and wet (January–March) seasons than at other times of the year. Juvenile P. semisulcatus catches were highest in the pre-wet season. While seasonal differences accounted for the highest proportion of variation in catches of tiger prawn postlarvae and juvenile P. semisulcatus, site was the most important factor for juvenile P. esculentus. In each season, catches of juvenile P. esculentus were highest in the shallow, open-coastline seagrass, where the biomass of seagrass was highest. The fact that the type of seagrass community appears to be more important to juvenile P. esculentus than to postlarvae, suggests that characteristics of the seagrass community may affect the survival or emigration of postlarval tiger prawns. Few prawns (<10%) from the seagrass communities in shallow waters exceeded 10.5 mm in carapace length. Despite the intensive sampling, growth was difficult to estimate because postlarvae recruited to the seagrass beds over a long period, and the residence times of juveniles in the sampling area were relatively short (∼8 wk).

We conducted field studies over three years to assess body burdens and maternal transfer of polychlorinated biphenyls (PCBs) as well as indices of sexual dimorphism in snapping turtles (Chelydra serpentina) of the upper Hudson River (NY, USA.) We collected adult turtles in areas known to be contaminated with PCBs and in nearby reference areas for measurement of body size, precloacal length, and penis size. We analyzed PCB concentrations in eggs collected over three years and in whole blood from adults in one year. Total PCB concentrations (mean +/- standard error) in eggs were 2,800 +/- 520 and 59 +/- 5 ng/g wet weight in the contaminated area and the reference area, respectively. Eggs from the contaminated area were significantly enriched in tri-, penta-, and hepta-PCBs relative to the reference area. Blood from adults in the contaminated area averaged 475 +/- 200 and 125 +/- 34 ng/g wet weight for males and females, respectively. In the reference area, blood PCB concentrations were 7 +/- 3 and 4 +/- 1 ng/g wet weight for males and females, respectively. Significant positive relationships were found between carapace length and blood PCB concentration for both sexes in the contaminated area; however, only a marginal relationship was found between female carapace length and concentration of PCBs in their eggs. Our results suggest that PCB contamination of the upper Hudson River presents risks of establishing high body burdens and of maternal transfer of PCBs to eggs, although our measures of gross morphology revealed no discernable expression of abnormal sexual development or reproduction.

Utility of streamer tags to assess survival and growth of juvenile tiger prawns ( Penaeus monodon) in aquaculture environments

Color, texture and flavor are all important determinants of seafood product quality and value. For shrimp, Penaeus monodon, one of the highest-priced shrimp species of the South-East Asia shrimp industry, dark tiger-striped coloration is a key product quality criterion. We evaluated the effects of leaf litter of the mangrove species Avicennia officinalis (AO), Heritiera fomes (HF), Sonneratia apetala (SA) and S.caseolaris (SC) on length, weight and body color of shrimp (Penaeus monodon) post-larvae (PL). Fifteen-day-old PL (weight: 0.01 g) were reared in 1100-L fiber-reinforced polyethylene tanks. Five treatments having three replications were conducted for four weeks. Four treatments received leaf litter of the four mangrove species and supplemental feeds and one control treatment was provided with supplemental feed only (FO). The pH, biological oxygen demand (BOD5), chemical oxygen demand (COD) and phytoplankton and zooplankton biomass were lower, while total ammonia nitrogen (TAN) concentration were significantly higher in the FO treatment than in treatments including leaf litter. PL survival averaged 89% and only differed significantly between the SA and SC leaf litter treatments (p < 0.05). After 4 weeks of culture, larvae in the FO treatment had significantly shorter body and carapace length, lower body weight and a lower specific growth rate than larvae in the other treatments, while SA-reared larvae attained significantly greater length and weight than in the other leaf litter treatments. Shrimp body coloration and pattern with leaf litter treatments were significantly different from the FO treatment. SA-reared larvae at harvest were significantly darker in body color than larvae reared with other mangrove species. Shrimp value chain stakeholders preferred dark shrimp as an indicator of organic production and higher price. Mangrove leaf litter was found to enhance the production and color quality of black tiger shrimp and this technique can be applied in commercial shrimp aquaculture.

The Arabian red shrimp, Aristeus alcocki Ramadan, 1938, is one of the targets of commercial trawlers operating since 2000 along the Indian coasts at depths of 200–850 m. We report for the first time on the reproductive biology, insemination frequency, ovarian maturation, gonadosomatic index (GSI), size at maturity, and fecundity of A. alcocki investigated macroscopically and validated histologically using monthly trawl samples from the southwestern coast of India. Females have an open thelycum with five gonad developmental stages (I to V) and two stages (I and II) in males. A total of 4,170 specimens were examined and 68.6% of the females had been inseminated (carapace length (CL) 22.0–53.0 mm), predominantly during January to May. Females in stage I (immature) measured on average CL 25.5 ± 0.87 mm, those in stages IV and V (mature) CL 41.5 ± 0.62 mm. Immature males were smaller, mean CL 20.5 ± 0.5 mm. Size at first sexual maturity for females was estimated as CL 35.07 mm (total length (TL) 120–170 mm) and the inseminated specimens (CL50is) were mature at CL 31.45 mm using a non-linear method. The smallest mature female was CL 35 mm, whereas the size at maturity (CL50ms) of males was estimated as CL 19.6 mm (TL 75–96 mm). We also report synchronous oocyte development and continuous spawning activity with a peak during January to April. Information on the reproduction of this deep-water shrimp will help fishery managers estimate the stock sustainability and develop resource management measures.

The purposes of this research were to analyze the growth of allometric and condition index of tiger shrimp (P.monodon) in Juata Laut waters and fishpond, Tarakan (Indonesia). The implementation of research for 3 months from January to March 2020. The research method used a quantitative descriptive with a case study and exploratory approach. The determination of the study area was done with purposive judgment sampling originating from the catch of trawl fishermen in Juata Laut waters and fishpond, Tarakan (Indonesia). A sampling of tiger shrimp (P.monodon) based on surveys of the catches from those two locations. The data collection method involved the differences between sex, total length, carapace length, and the total weight of tiger shrimp (P.monodon) in the Laboratory of Fisheries Biology, Faculty of Fisheries and Marine Science, University of Borneo Tarakan. The research variables were sex ratio, allometric growth, and condition index of male and female tiger shrimp. The results from Juata Laut waters obtained a sex ratio for males and females was 2:1 with a percentage of the male at 66.7% and female at 33.3%. The allometric growth, i.e., a total length and a total weight of male was positive and female was negative with a condition index of male and female for thin body shape was 56.3% and 50%; ideal body shape of 12.5% and female not found; fat body shape was 31.3% and 50%, respectively. The results from fishpond showed that the sex ratio for males and females was 1:1.52, with a percentage of 39.6% for males and females was 60.4%. The allometric growth of total length and total weight from the male was negative and female was positive with condition index of a male was 2.4% and female was not found; the thin body shapes was 32.7% and 48.4%; the ideal body of 2.4% and 1.6%; the fat body was 57.1% and 50% for each one; very fat body was 2.4% and female was not found.

This study investigates the length-weight relationships (LWR) of three economically important shrimp species (Farfantepenaeus aztecus, Penaeus semisulcatus, and Metapenaeus monoceros) in İskenderun Bay, Northeastern Mediterranean, using data collected between October 2023 and November 2024. A total of 579 specimens were analyzed, with F. aztecus contributing the highest sample size (238 individuals), followed by P. semisulcatus (214) and M. monoceros (127). Carapace length (CL) and weight (W) measurements revealed interspecies differences. The average carapace length was 5.66 mm for F. aztecus, 6.63 mm for P. semisulcatus, and 5.08 mm for M. monoceros. Average weights were 32.81 g, 39.68 g, and 31.48 g, respectively. Growth patterns, determined by the parameter 𝑏, showed distinct gender differences. Females generally exhibited negative allometric growth, while males displayed either isometric or positive allometric growth, depending on the species. Statistically significant differences in growth types were observed, particularly in M. monoceros males (p &lt; 0.05). These results provide crucial insights into the population dynamics and ecological adaptations of shrimp in İskenderun Bay. The findings contribute to understanding the species’ growth characteristics, supporting the development of sustainable fisheries management strategies in the region.

Nesting hawksbill turtles Eretmochelys imbricata and their eggs and young were studied on Cousine Island, Seychelles from 1995 to 1999. Numbers of females known to nest (tagged individuals) on Cousine was 146. An average of 75% of emerging adults were intercepted, and this rose to 81.6% in 1999. Mean carapace lengths and widths of adult females were 81.2 ± 60.8 cm, and included some of the longest carapace lengths known for hawksbill turtles. There were poor correlations between adult weight and carapace length or width, but better correlations between adult weight and the product of carapace length and width. Width to length carapace proportions averaged 0.75. The mean weight of nesting females before their first recorded nesting on Cousine was 65.6 kg (51.2–83.0 kg). These were the first recorded weights for nesting hawksbills from the Seychelles. Individuals lose 8.5–15% of their body weight after laying three to five clutches. Mean clutch size was 176.7, and clutch sizes for any season showed great variation for some individuals. Clutch sizes tended to decrease after the main nesting month for the population but not necessarily for the individual. The largest clutch size of 264 is the largest recorded for hawksbill turtles worldwide. Turtles with longer carapaces tended to lay larger clutches than those with shorter carapaces, and heavier turtles generally laid heavier clutches than did lighter turtles. Eggs were usually (85.6%) somewhat elongate, measuring on average 36.3 ± 35.5 mm, and weights averaged 25.5 g. Very few ‘pea’ eggs were found. The average hatchling weight was 14.5 g and the average carapace length and width were 39.2 and 30.1 mm, giving a mean ratio of carapace length to width of 0.77.