Gonad maturity level and somatic index of sea cucumber Acaudina sp. (caudinidae, molpadida, holothuroidea) In Delta Wulan Waters, Demak Regency, Indonesia

Sea cucumber Acaudina sp. belongs to the family Caudinidae, Order Molpadida, Class Holothuroidea. These animals have an important role in the benthic ecosystem. The purpose of this research was to determine the gonad maturity level and Gonad Somatic Index of Acaudina sp. in Delta Wulan Waters, Demak Regency. In total, 64 individuals of Acaudina sp. were taken in April 2021 and 148 individuals were taken in May 2021. In April observation, the highest gonad maturity level for females was at level 3, while the highest gonad maturity for male was at levels 1 and 2. Furthermore, in Mei observations, the highest gonad maturity level for females was at level 2 and for males, the highest gonad maturity level was at level 3. According to April observation, values GSI (Gonad Somatic Index) has a range 0.22 - 6.09 % and for May observation, value GSI has a range 0.04 – 2.24%. Hence, there is a positive correlation between gonad weight and GSI values in sea cucumber Acaudina sp.

Effects of GnRH and Anti-Dopamine on Gonad Maturation of Osteochilus melanopleurus (Bleeker, 1852)

The Osteochilus melanopleurus (Bleeker, 1852) is one of the endogenous fish in the Siak River waters of Riau province which has high economic value. However, the fulfillment of needs still depends on the catch in nature. Efforts to overcome these problems are the availability of mature gonads. Broadly to accelerate the maturation of gonads through hormone induction until the fish are ready to be spawned to produce fish fry continuously. The purpose of this study was to analyze the effect of gonadotropin and anti-dopamine hormone induction with the trademark “Oodev” on the final gonad maturity (TKG) of the prospective broodstock of O. melanopleurus. The research was conducted from April to August 2021 in the fish rearing column and the experimental pond, Faculty of Fisheries and Marine Science. The research method was a Completely Randomized Design with 4 treatment levels and 3 replications, while the treatments were P0 (without Oodev injection), P1 (Oodev dose 0.5 mL/kg), P2 (0.7 mL/kg), and P3 (0,9 mL/kg). Measured responses: percentage of broodstock that reached TKG and egg diameter. The results of the research that have been carried out, the measurement of the diameter of the eggs produced showed that the use of the Oodev hormone at a dose of 0.7 mL/kg body weight of O.melanopleurus given every week for twelve weeks was able to stimulate the development of the gonads of O.melanopleurus. Ovaprim injection of 0.7 mL/kg body weight produced 89,566 eggs with a latency of 4 hours. oodev injection dose of 0.7 ml/kg BW or P2 treatment has succeeded in achieving a TKG of 82%.

LENGTH-WEIGHT RELATIONSHIP AND REPRODUCTION OF SULPHUR GOATFISH Upeneus sulphureus (Cuvier, 1829) AT PPI KALIANDA, SOUTH LAMPUNG

Sulphur goatfish (Upeneus sulphureus) is the dominant caught with a fairly high level of utilization. This research aimed to analyze aspects of growth and reproduction sulphur goatfish caught by rampus nets landed at the fishing port of PPI Kalianda. Growth aspects that were observed included the length-weight, while the reproductive aspects observed is the sex ratio, gonad maturity level, and the size of sulphur goatfish at first maturity. This research was conducted in May-July 202 with the research method used simple random sampling method. The fish samples obtained during the study were 600 individuals, the results showed that Sulphur goatfish had negative allometric growth. The equation for the long-weight relationship of sulphur goatfish is log W = -4,6 + 2,9 log L or W = 2,8x10-5L2,9. The sex ratio of sulphur goatfish in May and July were not 1: 1, while the ideal condition was achieved in June. The gonad maturity level distribution of sulphur goatfish was dominated by TKG III and IV for female, while male sulphur goatfish was dominated by TKG II and III. Size at first maturity of sulphur goatfish females was 169,1 ± 1,03mm.

Biomorphometry of coconut crabs (Birgus latro) in Laigoma Island, North Maluku, Indonesia

Coconut crab is a coastal animal that lives in costal forest on islands of tropical Indo-Pacific. Crab populations are currently under threat of extinction. Several issues contribute to this, including high levels of exploitation, degradation of their native habitat, land clearance, and plantations development. This study aimed to examine the biomorphometric of coconut crabs, which includes the composition, sex ratio, distribution, widht and weight relation, condition factors and gonad maturity level. The descriptive explorative methods was used in this research. The results showed that the composition of 156 coconut crabs consisted of 82 females. The results obtained a balanced sex ratio. The size of the carapace width obtained ranged from 40.15 to 88.55 mm, with a weight of 150-565 grams. The relationship between width and capacity is allometric. The values obtained from these factors ranged from 1.01 to 1.03 for men and 1.01 to 1.012 for females. The gonad maturity level of male and female mud crabs was dominated by TKG III and IV. This indicated that the research time was in spawning period.

Length distribution, gonad maturity level, and catchable size of fish caught around FADs in Ternate Sea

Pelagic fishery business in Ternate Sea are mainly based on FADs fishing operations. Increase of intensive fishing activities will also increase the pressures on local pelagic fish resources of Ternate Sea in the future. So far, there has been limited scientific information related to the fish caught by local fishers. The aim of the study was to investigate length distribution, gonad maturity level (GML), and catchable size of fishes caught around FADs. The research was conducted in August 2020 in Ternate. The research method was a survey research by collecting samples of fish caught from gill nets and hand lines for total 30 fishing trips. The study results showed that the catch consisted of mackerel scads and yellow scads. The mackerel scads caught by gill nets were between 13-26 cm in size and dominated by the 19-20 cm size class, while fishes sizes caught by hand line were between 14-27 cm which were dominated by the 18-19 cm size class. Yellow scads caught with both gill nets and handlines showed the same length range of 12-23 cm, which was dominated by the size class of 18-19 cm. Mackerel scads caught with gill nets and handlines were dominated by fish in GML II (47%) followed by GML III (32%). GML of yellow scads caught with gill nets was dominated by GML III by 75%, while for fishes caught by hand line the percentage of GML III is 68%. The mackerel scads caught with gill nets and handlines were dominated by the non-catchable size category (100% for gill nets and 98.79% for handlines). On the other hand, all yellow scads caught with both gill nets and handlines are entirely (100%) of catchable size.

The dynamics of the liver weight and liver indices in the course of gonad maturation of gadid species on Eastern Kamchatka

Longterm data on the liver weight, hepatosomatic (HSI) and gonadosomatic (GSI) indices of walleye pollock, Pacific cod and saffron cod are analyzed on Eastern Kamchatka in seasonal aspect and in the course of gonad maturation. Individual values of the indices extensively vary and depend on the fish body length, season and stage of gonad maturity. The dynamics of the HSI is agree to the dynamics of the GSI during the year and depending on gonad maturity. The maximum values of the HSI are typical for walleye pollock and Pacific cod individuals with the gonads of the III stage of maturity. The maximum values of the index in saffron cod are found in mature individuals with immature gonads. The minimum values are demonstrated by the fish with the gonads at the stage of final spawning or of post-spawning recovery. During the annual reproduction cycle males and females of walleye pollock and cod realize different scenarios of spending and accumulating liver fat. Whereas the maximum HSI is observed in the fish with the gonads at the III maturity stage, the minimum values in males are typical for individuals with smelting gonads, and in females – on finishing the spawn. That can be connected to possible feeding for the individual. Liver weight and liver index can increase in males just shortly after finishing spawning, in females that is found only at the stage of post-spawning recovery.

Otolith “spawning zones” across multiple Atlantic cod populations: Do they accurately record maturity and spawning?

Specific changes identified in the otolith macrostructure of Northeast Arctic cod as “spawning zones” are presumed to represent spawning events, but recent experimental studies have challenged this relationship. Because these zones are not routinely recorded outside of Norway, otoliths from multiple Atlantic cod populations with different life history and environmental traits were first examined to see if spawning zones could be identified as a general characteristic of cod. Then, a large archival collection of cod otoliths was used to investigate temporal changes in the occurrence of spawning zones and test for correlations between maturity at age derived from otolith spawning zones and gonad maturity stages. This study shows that spawning zones likely are a universal trait of Atlantic cod and not limited to certain environments or migratory behaviors as previously proposed. Maturity at age derived from spawning zone data showed trends consistent with those from gonad examinations. However, spawning zones appear to form with a one- or two-year lag with sexual maturity, which is suspected to reflect a stabilizing of energy partitioning after the first spawning events. Our results illustrate the potential for use of spawning zones, for example in species or populations with limited available maturity data, and highlights the need for addressing the physiological processes behind their formation.

Biological Aspects of Waanders’s Hard-lipped Barbs (Osteochilus waandersii) in Tambatan River, North Sumatera, Indonesia

Background: Waanders’s hard-lipped barbs or scientifically known as Osteochilus waandersii belong to the family Cyprinidae with the potamodromous category. This fish can be found in the Tambatan river. It has the potential for commercial consumption or ornamental fish. Methods: This study was conducted in the Tambatan river from November to January 2021. The determination of three research stations was carried out using a purposive sampling method. Sampling was undertaken using cast nets. Furthermore, data analyzed were growth patterns, condition factors, and gonad maturity levels. Results: The growth patterns of male (1.944) and female (2.379) Osteochilus waandersii were in a negative allometric category. Besides, The Fulton's condition factor for male fish ranged from 0.42 - 3.43 with an average of 1.05, while that for female fish ranged from 0.59 - 3.67 with an average of 1.47. The result of the observation on the gonad maturity level for male and female O. waandersii in the Tambatan river indicated that they were dominated by fish with gonad maturity stage I (immature). Conclusions: Waanders’s hard-lipped barbs O. waandersii found were in the stage towards the mature level.

Effect of Giving Different Doses of Vitamin E in Feed to the Level of Gonad Maturity of Tilapia (Oreochromis niloticus)

One of the nutrients that can be given to brood feed fish to improve reproductive performance and egg quality is vitamin E. Vitamin E has a very important role in increasing fish reproduction because vitamin E functions as an antioxidant that can maintain the presence of fatty acids and prevent fat oxidation in the fish cell membrane and can accelerate the secretion of reproductive hormones. This study aims to determine the effect of vitamin E in feed at different doses on the level of gonad maturity of tilapia. The research was conducted at the Fisheries Laboratory of the Faculty of Marine and Fisheries, Udayana University from July to August 2020. The samples of fish tested were tilapia (Oreochromis niloticus) obtained from the Teratai fishing pond, Sanur Bali. Vitamin E used was Ovagrow Vit E with a vitamin E content of 50%. The CRD method (completely randomized design) was used with four treatments and three replications. The doses of vitamin E that were mixed into the feed were 0, 100, 300, and 500 mg/kg of feed. The results showed that the administration of vitamin E mixed in the feed at different doses had a significant effect on the achievement of gonad maturity level, gonad somatic index (GSI), and Fecundity (P <0.05). Provision of vitamin E at a dose of 300 mg/kg of feed was the best dose for ripening tilapia gonads. The gonad maturity level developed up to maturity stage IV, the GSI value was (3.56 ± 0.46) and the fecundity value was (1379 ± 289).