Reproductive traits and spawning activity of striped eel catfish (Plotosidae) in Kolono Bay, Indonesia

Asriyana A, Halili H. 2021. Reproductive traits and spawning activity of striped eel catfish (Plotosidae) in Kolono Bay, Indonesia. Biodiversitas 22: 3020-3028. Reproduction is a natural process for a species to ensure its sustainability in nature. This study aimed to investigate the reproductive traits and spawning activity of the striped eel catfish in Kolono Bay, South Konawe District, Southeast Sulawesi, Indonesia. A total of 965 individuals were collected monthly from June 2020 to May 2021 by using bottom experimental gillnets. Spent/spawning stages of the male and female fish were found during the East season (June-August). The proportions of the spent/spawning stages of male and female fish were 60% and 55.56% and the values of the gonadal somatic index were 1.19 ± 0.53 and 2.19 ± 3.47, respectively during the East season, indicate occurring the peak spawning in this season. Females matured gonads more rapidly at 198.3 mm compared to males at 224.5 mm. Female fecundity was 1,730 ± 390 eggs, with an egg diameter of about 0.11-1.35 mm. Striped eel catfish is a total spawner fish that has one mode of egg distribution pattern. During the East season, it needs protection for spawning. The findings will help in designing effective management and developmental strategies to conserve the striped eel catfish population in the future.

Gonad maturity and gonadal somatic index of blue swimming crab Portunus pelagicus harvested from Spermonde Archipelago, South Sulawesi, Indonesia

Reproductive biology is one of the biological aspects that needed to formulate responsible management of blue swimming crab (BSC). The crab is one of the commercial fisheries commodities in South Sulawesi, Indonesia. Presently no information on the reproductive biology of this crab from Spermonde Archipelago, Sout Sulawesi. Therefore, the study aimed to analyze and compare gonad maturity stage(GMS)andgonadalsomaticindex(GSI)oftheBSCcaughtonthreeecosystemsnamelycoralreef,seagrass,andmangrovein Salemo Island, Spermonde Archipelago. GMS and GSI were analyzed descriptively for five months from March to July 2015. Results indicate there was a difference in GMS of the BSC caught in mangroves, seagrass, and coral reef. Generally, mangrove was dominated by immature BSC with GMS I and GMS II, while the BSC caught in the seagrass and coral reef BSC were dominantly mature and spawn GMS III, IV, and V. GSI BSC caught in mangrove ecosystem are smaller than GSI BSC caught in seagrass and coral reef ecosystems. Seagrass and coral reef ecosystems suitable for development no-take zone of the BSC.

PENAMBAHAN VITAMIN E DALAM PAKAN TERHADAP KUALITAS REPRODUKSI INDUK IKAN NILA (Oreochromis niloticus)

Penambahan vitamin E sintetis pada pakan induk sangat penting, karena vitamin E tidak dapat disintesis oleh ikan. Tujuan penelitian ini adalah untuk mengetahui penambahan vitamin E dalam pakan terhadap kualitas reproduksi induk ikan nila. Penelitian dilakukan di Balai Riset Pemuliaan Ikan (BRPI) Sukamandi selama tiga bulan. Pakan uji adalah pakan formulasi berkadar protein kasar 35,83%-36,13%; lemak kasar 8,17%-9,79%; BETN 43,10%-45,72%; dan serat kasar 1,98%-2,58% dengan penambahan vitamin E berbeda, yaitu: A) 0 (kontrol), B) 150, C) 225, dan D) 300 mg/kg pakan. Ikan uji berumur 6,5 bulan sebanyak 80 ekor betina dan 40 ekor jantan, dan setiap induk ikan betina diberi tanda (tagging). Wadah ikan uji adalah jaring hapa berukuran 3 m x 2 m x 1,25 m sebanyak empat buah yang ditempatkan di kolam tanah seluas 6.000 m2 dengan ketinggian air ± 1 m. Setiap jaring diisi 20 ekor induk betina dan 10 ekor induk jantan. Parameter yang diamati adalah: gonad somatik indeks, frekuensi pemijahan, fekunditas, diameter telur, derajat tetas telur, produksi larva, abnormalitas larva, dan gonad pada akhir percobaan. Sampling dilakukan setiap satu minggu sekali selama tiga bulan pemeliharaan. Hasil penelitian menunjukkan bahwa penambahan vitamin E 225 mg/kg pakan memberikan hasil terbaik, dapat meningkatkan produksi larva sebesar 78,55% dibanding dengan tanpa penambahan vitamin E (kontrol). Jumlah induk memijah sebesar 85% dengan jumlah frekuensi pemijahan terbanyak yaitu 28 kali dan total produksi larva tertinggi yaitu 37.927 ekor (produktivitas induk 2.231 larva/ekor) dan rataan fekunditas individu sebesar 1.886 ± 513 butir.The addition of synthetic vitamin E in broodstock feed is a necessity due to fish inability to synthesized vitamin E. Currently, there is limited information on vitamin E requirement to boost the reproductive performance of tilapia. The purpose of this study was to determine the effects of vitamin E in feed on the reproductive performance of tilapia broodstock. The study was conducted for three months at the Sukamandi Fish Breeding Research Center. The test feeds were formulated feeds with crude protein content of 35.83%-36.13%, crude fat 8.17%-9.79%, NFE 43.10%-45.72%, and crude fiber of 1.98%-2.58% with the addition of different vitamin E, namely: A) 0 (control), B) 150, C) 225, and D) 300 mg/kg of feed. The test fish were aged 6.5 months consisted of 80 females and 40 males, where each female was given a unique tagging code. The fish were reared in four hapa nets sized 3 m x 2 m x 1.25 m which were constructed in a pond of 6,000 m2 with a water level of ± 1 m. Each hapa net contained 20 female and ten male broodstocks. The parameters observed were: gonadal somatic index, spawning frequency, fecundity, egg diameter, hatching rate, larval production, larval abnormalities, and gonadal development at the end of the experiment. Sampling was done once a week during the three months of the experiment. The results showed that the addition of vitamin E 225 mg/kg of feed gave the best results. Larval production increased by 78.55% compared to without the addition of vitamin E (control). The percentage of spawning broodstock was 85% with the highest number of spawning frequencies of 28 times, the highest total larvae production of 37,927 larvae (broodstock productivity 2,231 larvae/fish), and the average individual fecundity of 1,886 ± 513 eggs.

Tangkapan dan tingkat kematangan gonad Ikan selar kuning (Selariodes leptolepis) di Perairan Selat Malaka

Biologi reproduksi meliputi distribusi frekuensi panjang, hubungan berat-panjang tubuh, rasio jenis kelamin, tingkat kematangan gonad (TKG), indeks somatic gonad (IKG), diameter telur. Data primer yang digunakan adalah panjang dan berat tubuh, bobot dan gonad Ikan yang diperoleh dari 360 ekor sampel. Data sekunder dikumpulkan dari Laporan Statistik Perikanan PPS Belawan berupa jumlah produksi, dan jumlah tangkapan ikan tahun 2011-2016. Hasil penelitian menunjukkan distribusi frekuensi panjang ikan berkisar antara 110 mm - 163 mm. pola pertumbuhan ikan adalah alometrik negatif dengan koefisien korelasi jantan dan betina mendekati 1 yaitu 0,812 dan 0,733. Indeks kematangan gonad untuk ikan betina adalah lebih besar dibanding ikan jantan. Tingkat kematangan gonad diperoleh dari tingkat I, II, III, dan IV.Reproductive biology including length frequency distribution, long weight relationship, sex ratio, gonadal maturity level, gonadal somatic index and egg diameters. Primary data used is lenght and body weight. Weighting obtained as many as 360 samples. Secondary data was collected from Fishing Statistical Report of PPS Belawan, which were the amount of production, and fishing effort of the year 2011-2016. The results showed the frequency distribution of fish length of 110 mm – 163 mm. Character growth negative allometric with a correlation coefficient males and females approximate to 1 whereas 0.812 and 0.733. Gonadal maturity index for females fish than large from males fish. Gonadal maturity index obtained by the I, II, III, and IV.

Development of fish tests for endocrine disruptors

International concern over endocrine active substances (EASs) has led to intensive research programmes to establish fish reproductive and developmental toxicity tests for use in environmental (ecological) risk assessment. This chapter gives an overview of key themes of in vivo ecotoxicology research, including fish screening assays, partial life-cycle tests (the draft OECD fish reproduction test and the new fish development test) and fish full life-cycle tests. In the context of the OECD test guidelines program, fish species of primary interest include fathead minnow, medaka and zebrafish, while guppy, rainbow trout, sheepshead minnow, and three-spined stickleback are also of scientific importance. Critical factors for evaluation include baseline reproductive biology and definition of EAS sensitive life-stages. For regulatory applications, a critical review of existing fish EAS data suggests that apical adverse effect endpoints, namely development, growth and reproduction (e.g., fecundity, fertilization rates, and hatching success) should be used to derive predicted no-effect concentrations (PNECs) for the environmental risk assessment of EASs. In support of these apical adverse effect endpoints, biomarker responses (e.g., vitellogenin, gonadal-somatic index, and gonad histopathology) should be used to provide mechanistic data, compare species (e.g., cyprinids vs. salmonids), and allow extrapolation between laboratory and field studies.

Influence of Haemobaphes cyclopterina and H. intermedius (Copepoda) on Arctic cod (Boreogadus saida) and tidepool sculpins (Oligocottus maculosus), respectively

A study was conducted to determine the prevalence and effects of two species of blood-feeding copepods on their definitive fish hosts, viz. Haemobaphes cyclopterina parasitizing Arctic cod (Boreogadus saida) and H. intermedius infecting tidepool sculpins (Oligocottus maculosus). Infected and uninfected Arctic cod and tidepool sculpins were captured by SCUBA and dip net in the northwest Atlantic and northeast Pacific, respectively. Biological variables such as condition factor, hepatic somatic index, gonadal somatic index, and haematocrit were compared between the two groups of Arctic cod of both sexes, whereas only condition factor was compared in the two groups of sculpins of both sexes. Prevalence of H. cyclopterina (8%) was considerably lower than that of H. intermedius (46%). This difference is probably associated with the hosts' behaviour, as the Arctic cod is pelagic whereas the tidepool sculpin is restricted to the littoral zone, where infections are probably acquired. Infected Arctic cod of both sexes had significantly lower condition factor, hepatic and gonadal somatic indices, and haematocrit than non-parasitized fish. Only females harboured large numbers of the parasite and showed even more dramatic changes than the corresponding groups. The growth period of H. cyclopterina on Arctic cod from the time of infection to the fully developed egg sac stage is probably about 6 months. In tidepool sculpins, condition factor was significantly lower in infected than in uninfected fish. These results, especially for the Arctic cod, parallel those reported for gadoid fish following infection with haematophagous species of Lernaeocera that impair growth and reproduction.