Reproductive Characteristics of the Pond-Farmed Sultan Fish (Leptobarbus hoevenii)

Highlight ResearchThe reproductive characteristics of L. hoevenii were examinedThe potentially smallest maturity sizes of female and male L. hoevenii were 350 g and 180 g, respectivelyThe fecundity of a 1,000 g L. hoevenii can be more than 100,000 eggsL. hoevenii was determined as a multiple spawnerAbstractSultan fish (Leptobarbus hoevenii) is a high value freshwater fish, cultured in some Southeast Asian countries, including Malaysia and Thailand. However, information on its reproductive characteristics is very scarce. This study examined the gonadosomatic index (GSI), fecundity, egg diameter, and determined whether L. hoevenii is a single- or multiple-spawner. Twenty male and female pond-farmed L. hoevenii broodstock were obtained to measure their total length (TL), body weight (BW) and gonad weight to calculate the GSI. Ten females were randomly sampled from the 20 to determine their fecundity. A total of 1,500 eggs were sampled from each female. The egg diameter was measured then its frequency distribution was analyzed to detect the number of egg class group, and to determine whether L. hoevenii is a single- or multiple spawner. The female L. hoevenii examined were 32.2-47.1 cm and 350-1,200 g, while the males were 30.7-45.8 cm and 180-970 g in TL and BW, respectively. All female specimens contained gonads. The potentially smallest mature samples were recorded at 350 g (female) and 180 g (male). GSI for the female and male L. hoevenii were 1.81-12.28 % and 1.03-5.09 %, respectively. The fecundity was 35,467 -128,067 eggs, while the highest fecundity was observed in a 1,000 g fish. The observed egg diameter ranged from 500 to 1,855 μm. Two to five groups of egg class were detected, indicating that L. hoevenii is a multiple spawner.

New Evaluation of Postovulatory Follicle Degeneration at High-Temperature Regimes Refines Criteria for the Identification of Spawning Cohorts in the European Anchovy (Engraulis encrasicolus)

Accurate stock assessment estimates of fish resources are essential in fishery management. Wide fluctuations in abundance arising from variations in reproductive success are characteristic of many marine fish populations, including multiple spawner species. The proportion of females spawning per day is crucial in the application of egg production methods for spawning biomass evaluation and, usually, is assessed by postovulatory follicle (POF) method. Describing each degeneration stage of POF based upon its histological features allows for obtaining an aging key for postovulatory follicles. The commercially valuable European anchovy (Engraulis encrasicolus) was selected as a case study, which breeds during the summer in temperate waters (24 °C–25 °C). A collection of ovary slides, sampled in the central Mediterranean Sea during the spawning peak, provided a 24 h cycle coverage. These observations allowed us to evaluate the duration of each POF stage at water temperature experienced by anchovy in the study area. Present results demonstrated the POF degeneration progress at a faster rate than reported by previous investigations, carried out in cooler oceanic waters. Furthermore, the present study displayed the presence of two anchovy spawning cohorts sampled along a 24-h cycle. Therefore, this study not only provides useful insight for more accurate POF degeneration evaluation in temperate waters, but also suggests that current estimates should be complemented with validation studies according to different temperature regimes.

Reproductive biology of Parona signata (Actinopterygii: Carangidae), a valuable economic resource, in the coastal area of Mar del Plata, Buenos Aires, Argentina

ABSTRACT The reproductive biology and life cycle of Parona leatherjacket, Parona signata, present in Mar del Plata (38º 00’S 57º 33’W) coast, was studied. Samples were obtained monthly since January 2018 to February 2019 from the artisanal fishermen and the commercial fleet of Mar del Plata. A histological analysis was carried out and the main biologic-reproductive parameters were estimated: fecundity, oocyte frequency distribution and gonadosomatic index (GSI). Both the macroscopic and microscopic analyses showed reproductive activity in March and November. Mature females were recorded, which showed hydrated oocytes, as was evidenced by the histological procedures. Both, the histological and the oocyte diameter distribution analyses showed the presence of all oocyte maturation stages in ovaries in active-spawning subphase, indicating that P. signata is a multiple spawner with indeterminate annual fecundity. Batch fecundity ranged between 36,426 and 126,035 hydrated oocytes/ female. Relative fecundity ranged between 42 and 150 oocytes/ g female ovary free.

PENENTUAN UKURAN PERTAMA KALI MATANG GONAD (Lm) CAKALANG (Katsuwonus pelamis Linnaeus, 1758) DI SAMUDRA HINDIA SELATAN BALI

Cakalang tergolong kelompok jenis ikan pelagis besar yang keberadaanya cukup melimpah di perairan Samudera Hindia termasuk perairan selatan Bali. Informasi biologi reproduksi sangat penting terutama untuk mengetahui kapan ikan tersebut memijah sehingga dapat digunakan sebagai dasar pengelolaannya. Cakalang memijah beberapa kali (multiple spawner), hal ini diketahui berdasarkan tingkat perkembangan oosit yang lebih dari satu tingkatan dalam satu gonad aktif. Sampel gonad cakalang betina diperoleh dari Pangkalan Pendaratan Ikan Kedonganan, Bali. Sebanyak 106 ekor cakalang betina dengan kisaran panjang cagak 37-71 cmFL dan kisaran bobot 902-7.214 gram yang teramati. Sampel gonad dalam keadaan segar langsung difiksasi menggunakan larutan buffer-formalin 10% kemudian dianalisis secara histologis menggunakan metode parafin dan pewarnaan HE (Harris-Haemotoxilin dan Eosin). Cakalang betina yang diklasifikasikan sebagai ikan yang belum dewasa (immature) memiliki karakteristik oosit unyolked (UY) yang lebih gelap pewarnaannya, memiliki diameter <156 µm dan Early yolked (EY) yang memiliki diameter 114-249 µm. Cakalang dewasa (mature) memiliki karakteristik perkembangan ovari berupa adanya oosit pada tingkat yang lebih tinggi yaitu advanced yolked (AY) dengan diameter oosit berkisar antara 180-448 µm, migratory nucleus (MN) 239-468 µm dan hydrated (Hy) dimana ukuran oositnya sangat besar yaitu sekitar 459-552 µm dan berbentuk seperti noda merah muda (pink stain). Cakalang betina di perairan Samudera Hindia selatan Bali memiliki perkembangan oosit yang asynchronous (tidak seragam) yang ditandai oleh munculnya beberapa tingkat perkembangan oosit dalam satu ovari. Ukuran panjang pertama kali matang gonad (Lm) cakalang betina yaitu 44,7 cmFL. Cakalang betina dewasa yang berstatus memijah aktif (actively spawning) ditemukan di setiap bulan pengamatan (April-September) dan diduga memijah sepanjang tahun. Skipjack tuna is classified as a large pelagic fish species and has abundant presence in the waters of the Indian Ocean including the waters of southern Bali. Information related to reproductive biology is very important especially to find out when the fish spawn so that they can be used as a basis for its management. Skipjack spawns several times (multiple spawner), this is known based on the level of oocyte development that was more than one level in one active gonad. Samples of female skipjack gonads were obtained from Kedonganan, Bali. A total of 106 female skipjack tuna with length range of 37-71 cmFL and weight range of 902-7,214 grams were observed. Gonad samples in fresh condition were immediately fixed using a 10% buffer-formalin solution then histologically analyzed using the paraffin method and HE staining (Harris-Haemotoxilin and Eosin). Female skipjack classified as immature fish has the characteristics of unyolked oocytes (UY) which are darker in coloration, have a diameter <156 ìm and Early yolked (EY) which has a diameter of 114-249 ìm. Adult skipjack (mature) has the characteristics of ovarian development in the form of oocytes at a higher level, namely advanced yolked (AY) with oocyte diameter ranging from 180-448 µm, migratory nucleus (MN) 239-468 µm and hydrated (Hy) where oocyte size is very large, which is around 459-552 µm and shaped like a pink stain. Female skipjack in the waters of the Indian Ocean south of Bali has an asynchronous (non-uniform) oocyte development which is characterized by the appearance of several levels of oocyte development in one ovary. Size at first maturity (Lm) of female skipjack in Indian Ocean southern Bali was 44.7 cmFL. Adult skipjack females with active spawning status are found every month of observation (April-September) and suspected to spawn throughout the year.

BIOLOGI REPRODUKSI SELAR BENTONG (Selar crumenophthalmus Bloch, 1793) DI PERAIRAN KWANDANG, GORONTALO UTARA

Ikan selar bentong (Selar crumenophthalmus Bloch, 1793) merupakan salah satu ikan ekonomis penting yang tertangkap di perairan Kwandang, Sulawesi Utara. Penelitian ini bertujuan untuk mengetahui biologi reproduksi ikan selar bentong. Pengumpulan data panjang berat, jenis kelamin dan tingkat kematangan gonad dilakukan dari periode Februari hingga November 2017. Jumlah contoh ikan yang diamati sebanyak 3.820 ekor. Hasil penelitian ini diperoleh persamaan hubungan panjang-berat ikan selar bentong yang diukur yaitu W = 0,0092 L3,1857. Nilai b dari persamaan ini adalah 3,18 yang mengindikasikan bahwa pola pertumbuhannya bersifat isometrik. Ukuran pertama kali matang gonad (Lm) adalah 17,69 cmFL. Rasio kelamin antara betina terhadap jantan yaitu 1 : 1,2. Musim pemijahan atau bersifat multiple spawner diduga terjadi antara Bulan November – Februari.Bigeye scad (Selar crumenophthalmus Bloch, 1793) was one of the important economic species in the artisanal fishery in Kwandang waters North, Sulawesi. The aim of this study was to determine the biological reproduction of big eye scad in the Kwandang waters, Sulawesi Sea. Data collection of lengths and weights, sex, and the gonad maturity stage were done between January-November 2016. A total of 3820 specimens was collected al together and examined in the study. The result showed that length-weight relationship for big eye scad were W = 0,0092 L3,1857. The exponent values (b slope) of length-weight relationship of big eye scad was 3,185 indicating isometric growth pattern. The length at first maturity (Lm) for bigeye scad was 17,69 cmFL. The sex-ratio between female and male was 1 : 1.2. The spawning season was estimated between November and February (multiple spawner).

GONAD MATURITY STAGES OF ANCHOVIES (Encrasicholina heterolobus) FROM BACAN ISLAND

The gonad maturity stages of anchovies (Enrasirholina hetentlobus) used as tuna baitfish were examined in the waters of Bacan Island. The species is a multiple spawner with asynchrounous oocyte development.

BEBERAPA ASPEK BIOLOGI IKAN TENGGIRI PAPAN (Scomberomorus guttatus) DI PERAIRAN CILACAP DAN SEKITARNYA

Tenggiri papan (Scomberomorus guttatus)merupakan ikan yangmemiliki nilai ekonomis penting dan banyak tertangkap dengan gillnet di perairan Cilacap dan sekitarnya. Pada saat ini terdapat kecenderungan ukuran individu yang mengecil. Tujuan Penelitian ini adalah mengetahui beberapa aspek biologi ikan tenggiri papan meliputi sebaran ukuran panjang, hubungan panjang-bobot, nisbah kelamin, tingkat kematangan gonad dan ukuran rata-rata pertama kali matang gonad, berdasarkan hasil tangkapan gillnet yang didaratkan di Pelabuhan Perikanan Samudera Cilacap pada bulan Februari sampai Desember 2013. Hasil penelitian menunjukkan ukuran panjang cagak berkisar antara 11 – 67cm. Pola pertumbuhan ikan tenggiri papan bersifat isometric dimana pertambahan panjang dan bobotnya seimbang. Nisbah kelamin jantan terhadap betina sebagai 1 : 0,7. Panjang pertama kali ikan tertangkap (Lc) dengan gillnet berukuran mata jaring 3 inchi sebesar 32,7 cmFL dan pertama kalimatang gonad (Lm) sebesar 42,34 cmFL. TingkatKematanganGonad (TKG) ikan jantan dan betina didominasi oleh stadia IV terutama pada bulan Februari dan Mei. Hasil penelitian ini menunjukkan dugaan awal masa pemijahan terjadi pada bulan Maret dan Juni, dengan demikian pemijahan dilakukan secara bertahap. Indo-Pasific king mackerel (Scomberomorus guttatus) is one of fish that has an important economic value.The species were many caught by gillnet in Cilacap and adjacent waters. Research was conducted to determine biological aspect of Indo-Pasific king mackerel that includes length distribution, length-weight relationship, sex ratio, maturity stage and length at first mature, based on monthly catches landed at Cilacap fishing port during February to December 2013. The results showed that folk length ranged from 11 to 67 cm. The growth pattern are isometric. The condition of sex ratio ofmales to females was 1 : 0,7. Length at first capture(Lc) by gillnet with mesh size of 3 inches was 32.7 cmFL and length at first maturity(Lm) was 42.34 cmFL. The gonade maturity stage of males and females were dominated by stage IV mainly in Febuary and May. It was indicated that spawning seasons occured in March and June. It was indicated that the fish has multiple spawner.

The reproductive biology of Pinguipes brasilianus Cuvier, 1829 (Osteichthyes: Pinguipedidae) in temperate rocky reefs of Argentina

ABSTRACT Pinguipes brasilianus is a conspicuous and abundant rocky-reef fish inhabiting the Northern Patagonian gulfs of Argentina, Southwest Atlantic. This study describes its reproductive biology in this region. We made macroscopic and histological descriptions of the testis and ovary development, analyzed the evolution of the gonadosomatic index (GSI) in both sexes throughout the year, and estimated fecundity and length at 50% maturity for females. Pinguipes brasilianus is a multiple spawner with indeterminate annual fecundity and an extended reproductive season, encompassing austral spring and summer. Low GSI values in males (monthly means ranged between 0.11% and 0.75%) and low relative fecundity in female fish (between 2 and 44 oocytes/g) are consistent with a need of close proximity between male and female during oocyte fertilization, sexual courtship and with spawning in pairs and/or within reef crevices. The estimated length at 50% maturity (± SD) for females was 15.22 ± 0.43 cm total length. Although P. brasilianus shares the main reproductive features of its congeneric species Pinguipes chilensis , male GSI and female length at 50% maturity in P. brasilianus were markedly lower than those reported for P. chilensis , while relative and batch fecundity were greater in fish of the same size.

Ovary maturation stages histology and follicles diameter of Melanotaenia boesemani rainbowfish ovary from district of North Ayamaru, Maybrat Regency, west Papua

Introduction: This research aim is to described ovary maturation stages histologically related with oocytes development in ovary of boesemani rainbowfish M. boesemani from North Ayamaru district, Maybrat Regency, West Papua. Materials and Methods: A histologycal analysis of ovari maturation stage (OMS) of the Boesemani rainbowfish Melanotaenia boesemani performed on 93 ovaries. Fresh ovaries were fixed in 10% Neutral Buffered Formalin (NBF) and embedded in paraffin. Section of about 5-6 pm thickness were cut and stained with Hematoxylin eosin (HE). Results: Histologycal analysis of rainbowfish M. boesemani ovaries based on oocyte development consist of 8 oocyte types not included atresia follicle i.e oogonia, early perinuclear oocyte, late perinuclear oocyte, cortical alveoli oocyte, early vitelogenic oocyte, mid-vitelogenic oocyte, late vitelogenic oocyte, and mature oocyte. The chorion and follicle layers begins to form at OMS II, keeps growing at OMS III, and was apparent at OMS IV. The chorion and follicle layers at OMS V ovaries were disintegrated. Conclusion: Based on ovary histology, oocyte proportion, and follicles diameter distribution can be concluded that the rainbowish M. boesemani classiied as multiple spawner.