Chromobotia Research Articles

Production performance and business analysis of clown loach Chromobotia macracanthus (Bleeker 1852) in recirculating systems with different stocking densities and water discharge

Efforts to improve the production performance of clown loach in recirculate aquaculture system can be done by increasing stocking density and water discharge. This study aimed to analyze the effect of increasing stocking density and water discharge on production performance, stress response and water quality in order to obtain the best stocking density and water discharge to obtain maximum profit in a short time. A factorial completely randomized design with two factors, i.e. the stocking density of 1, 2, and 3 fish L-1 and the water discharge of 0,05; 0,10; 0,15 L s-1 was performed. The volume of water used in each aquarium was 48 L and using a ½ inch faucet stop to regulate the water discharge from the inlet pipe. Clown fish fed Tubifex sp. with a feeding frequency of two times a day according to the treatment for 60 days. The result indicates that there was no interaction between the two factors on production performance, payback period, and R/C ratio. Stocking density has a significant effect on specific growth rate, absolute growth rate of individual weight, feeding consumption rate and R/C ratio of clown loach. Stocking density and water discharge had an interaction on the visual color of pectoral and caudal fins of clown loach. Different stocking densities with the combination of water discharge in this study resulted that the water quality were within tolerable range for clown loach so that they did not experience stress, as well as high production and business performance. It is recommended to intensify clown loach with a stocking density of 3 fish L-1 and 0,15 L s-1‑ of water discharge.

The honey solution effect as a natural cryoprotectant on sperm quality of botia, Chromobotia macracanthus Bleeker 1852

The purpose of study was to obtain the best combination of natural cryoprotectant (honey solution) and synthetic cryoprotectant (methanol) on the quality of spermatozoa Chromobotia macracanthus Bleeker 1852, after freezing at -80 ℃ for 48 hours. The combination of 10% methanol with various concentrations of honey solution (0%, 0.1%, 0.3%, 0.5%, 0.7% and 0.9%) was tested in this study. Ringer's solution was used as an extender. The diluted sperm was then equilibrated for 25 minutes at 4 ℃, then frozen at -80 ℃ for 48 hours. The sperm was then thawed at 40 ℃ for 13 seconds. Viability, motility and percentage of fertilization were evaluated. The results of the analysis of variance showed that the combination of 10% methanol with several concentrations of honey solution had a significant effect (P <0.05) on the viability of spermatozoa and the percentage of fertilization, but had no effect on sperm motility (P> 0.05). The combination of 0.1% honey solution and 10% methanol showed the highest percentage of both motility (89.4 ± 5.45%), viability (85.75 ± 4.79%), and the percentage of fertilization (98.55 ± 1.69%). %). The conclusion of this study is that 0.1% honey solution combined with 10% methanol in Ringer's solution is the best cryoprotectant for C. macracanthus spermatozoa stored at -80 ℃ for 48 hours

Improved performance of botia fish Chromobotia macracanthus with the utilization of blood clam shell in the recirculation system

ABSTRACT
 
 Intermediate and holding rearing of botia face several problems such as the limited land, water quality, and decreased growth. The application of a recirculation culture system using the blood clam filter is increased to water quality and expected to solve the problems. This study aimed to analyze the production performance of botia fish on intermediate and holding rearing in the recirculation system by utilizing blood clams as the filter. This study used a factorial completely randomized design with two factors; clam particle sizes (1 mm, 2 mm, and 3 mm) and dosages (1.4 g/L, 1.8 g/L, and 2.2 g/L). Every experiment was conducted in three replication. The aquarium used in this study was 40×40×60 cm3. The size of fish samples was 3.5 ± 0.5 cm with the stocking density (3 fish/L, each test aquarium). The recirculation system was applied seven days before the fish were stocked. Every 15 days, weight and length of fish were measured (for 60 days). The results of physical (temperature) and chemical (pH, dissolved oxygen, ammonia dan nitrite) water quality in the recirculation system using the blood clam filter showed good conditions for botia fish. The stress response of botia blood glucose and TKO fluctuates with environmental changes. Mineral water and fish produced by calcium, magnesium, and phosphorus increase until the end of maintenance. There is an interaction at TKH between particle size and the dose of blood shells, whereas, LMPW, LMPL, and RKP significantly different only the use of dose 2.2 g/L.
 
 Keywords: Clamshells, botia fish, pH value, minerals, recirculation.
 ABSTRAK
 
 Permasalahan pada proses penampungan ikan botia yaitu keterbatasan lahan, kualitas air yang buruk dan pertumbuhan ikan botia yang lambat. Penerapan sistem resirkulasi menggunakan cangkang darah dapat meningkatkan kualitas air dan kinerja produksi. Penelitian ini bertujuan menganalisis kinerja produksi budidaya ikan botia pada sistem resirkulasi dengan pemanfataan cangkang kerang darah sebagai bahan filter. Penelitian ini menggunakan rancangan acak lengkap faktorial dua faktor, yaitu ukuran partikel cangkang kerang darah (1 mm, 2 mm, dan 3 mm) dan dosis cangkang kerang darah (1.4g/L, 1.8g/L dan 2.2g/L). Setiap perlakuan dilakukan dengan tiga kali ulangan. Akuarium yang digunakan dalam penelitian berukuran 40×40×60 cm3. Ikan yang digunakan berukuran 3.5 ± 0.5 cm dengan padat tebar 3 ekor/L. Sistem resirkulasi dioperasikan selama tujuh hari sebelum ikan ditebar. Bobot dan panjang ikan diukur setiap 15 hari selama 60 hari pemeliharaan. Penelitian dalam sistem resirkulasi menggunakan cangkang kerang darah pada media filter menghasilkan kondisi kualitas air suhu, pH, oksigen terlarut, amonia dan nitrit air. Respons stres ikan berupa glukosa darah dan tingkat konsumsi oksigen (TKO) berfluktuasi seiring dengan perubahan lingkungan. Mineral air dan ikan yang dihasilkan meliputi kalsium, magnesium dan fosfos meningkat hingga akhir pemeliharaan. Parameter tingkat kelangsungan hidup (TKH) memiliki interaksi antara ukuran partikel dan dosis cangkang kerang darah, sedangkan untuk laju pertumbuhan bobot mutlak (LPMB), laju pertumbuhan panjang mutlak (LPMP) dan rasio konversi pakan (RKP) berbeda nyata dengan penggunaan dosis 2.2 g/L.
 
 Kata kunci: Cangkang kerang darah, ikan botia, pH, mineral, resirkulasi.

Botia (Chromobotia macracanthus Bleeker, 1852) Potential Broodstock Rearing With and Without Shelter

Botia fish (clown loach) growth is relatively slow, taking 4-5 months to reach marketable size (2 inch) and 3 years to achieve initial gonad maturation in female and 1 year in male fish. Environmental degradation and overfishing are factors triggering the production of newly potential broodstock. This study aimed to observe the growth response of potential broodstock through rearing technique with and without shelter. Fish were kept inside the aquaria sized 80x40x30 cm with 20 cm water height on the recirculation system. Fish used for shelter treatment were: Total length ± 7.7 cm, height ± 2.09 cm, and weight ± 7.33 g; for no shelter treatment were: Total length ± 6.7 cm, height ± 1.88 cm, and weight ± 4.59 g. Fish were stocked 10 fish / aquarium and fed 3 times / day by at satiation method. Parameters observed were total length, height and weight improvement also water quality. The results showed that growth and feed efficiency had better value when reared with shelter than without shelter. Keyword: Grow-out, Chromobotia macracanthus, shelter

Promoting Color Brightness of Clown Loach (Chromobotia macracanthus Bleeker) by Mixing Red Spinach (Amaranthus tricolor L.) Powder with Feed Stuff

The purpose of this research is to determine the optimal dose of the addition of red spinach powder to artificial feed on the brightness of clown loach. This research was conducted at Aquaculture Laboratory Building 4 Faculty of Fisheries and Marine Sciences of Universitas Padjadjaran from April to May 2020. This research method is experimental with a Completely Randomized Design consisting of four treatments and three replications. The red spinach powder addition treatment used 0%, 2%, 4%, and 6% of the feed amount. The parameters observed are color value as primary data by using Toca Color Finder, while the growth, survival rate, and water quality as support data. Color assessment results were analyzed using the Kruskal-Wallis test, if there were significant differences, Z test would be performed. Growth data and survival rates were analyzed using Analysis of Variance (ANOVA). Because the F test results were not significantly different, the Duncan test was not carried out. The results showed that the addition of 6% red spinach powder is the best treatment with an increased color brightness value of 5,63.

Rearing and Spawning Technique of Clown Loach (Chromobotia macracanthus, Bleeker 1852) in Research Institute for Ornamental Fish Culture of Depok, Indonesia

The high demand of botia fish (Chromobotia macracanthus) in the market lead to its sustainability in nature being threatened. The purpose of this technical report is to describe the broodstock and spawning techniques of botia fish carried out at the Research and Cultivation Center for Freshwater Ornamental Fish (BRBIH) Depok, West Java. This activity was carried out from December 2019 to January 2020. This study used two female cows with a spawning ratio of 3 : 1. The average length of the female parent is 9.5 cm with an average weight of 33.5 g, while the length of the male parent is 15.3 cm with an average weight of 56.3 g. Spawning is done artificially using ovaprim. The result of this study was the fecundity value of an average of 8 453 eggs / ind. The average FR was 86.15 %, and the average HR was 78.15 %.

Color quality and antioxidant activity evaluation of clown loach juvenile, Chromobotia macracanthus Bleeker 1852 by addition of astaxanthin in diet

Botia or clown loach is the one of fishes was originated from Indonesia and as an ornamental fish commodity in the global market. Clown loach both nature and cultured have some problems when reared in aquaria that is the decrease of color quality. An innovation technology to improve color quality through diet formulates is needed. The aims of this research were to increase the color quality using astaxanthin in diet and to find out the role of astaxanthin as antioxidant in clown loach. The study consists of four treatments of astaxanthin dosages in the diet with isoprotein and isoenergy, namely 0, 50, 100 and 150 mg kg-1 with four replications. The fish juveniles with size of 3.44±0.51 cm and 0.56±0.02 g of weight with density of one fish per littre were used. The test diet was given three times a day during 60 days. The results showed that there were no significant differences antioxidant activity such as superoxide dismutase enzymes and malondialdehyde. However, there was a significant effect (P<0.05) to color quality of the chroma and total carotenoid, whereas no significantly different in lightness. The addition of astaxanthin was effective to improve the color quality of clown loach juvenile. Thus, 100 mg kg-1 of astaxanthin in diet is an optimal dose for clown loach juvenile.

Effect of Tubifex and Carrot Meal Combination on Color Quality of Botia Chromobotia macracanthus

Colour is the most important indicators of quality in ornamental fish, making the exploration to find new sources of pigments in ornamental fish is growing. This study aimed to determine the optimum dose of tubifex and carrot meal combination to enhance the quality of color in Botia Chromobotia macracanthus. This study was designed using Completely Randomized Design with six treatments in triplicates: a) commercial feed (control), b) 70% Tubifex + 3% carrot meal + 27% commercial feed, c) 60% Tubifex + 4% carrot meal + 36% commercial feed, d) 50% Tubifex + 5 % carrot meal + 45% commercial feed, e) 40% Tubifex + 6% carrot meal + 54% commercial feed, and f) 30% Tubifex + 7% carrot meal + 63% commercial feed. Parameters observed were color change level, which was tested using the Kruskal-Wallis method; survival rate (SR) tested using analysis of variance through the F test; and water quality. Results showed that the best color enhancement seen in treatment with 50% Tubifex + 5% carrot meal + 45% commercial feed combination with an average body color of 5.04 in Toca Colour Finder code 0605. The caudal fin color was enhanced with an average score of 3.93 in code 0805.

Effects of different live feed on growth and survival rate of clown loach, Cromobotia macracantus

This study aims to investigate the effect of different types of live feed on the growth and survival of clown loach, Cromobotia macracanthus. We used a completely randomized design with four treatments and five replications. The treatments were A; commercial diet feeding as control, B; silkworm, C; golden snail, D; sea worm. The feeding rate was 5% of body weight and feeding frequency was twice per day fed for thirty days. Tested parameters were weight gain (WG), length gain (LG), specific growth rate (SGR), feed conversion ratio (FCR) and survival rate (SR). The result showed that the administration of different live feed had a significant effect on growth performances (p <0.05) of clown loach fingerlings, but did not significantly affect its survival rate. The optimum weight gain (WG), length gain (LG), specific growth rate (SGR), feed conversion ratio (FCR) were found at treatment B, silkworm feeding with 0.78 ± 0.02 g, 4.33±0.01 cm, 0.47 ± 0.01%/day and 2.44 ± 0.08 respectively. Therefore, we concluded that the silkworm was highly recommended for clown loach, Cromobotia macrancantus fingerlings feeding.

Dietary free glutamine supplementation to increase physiological responses and survival rate of clown loach juvenile, Chromobotia macracanthus Bleeker, 1852

Clown loach Chromobotia macracanthus is one of Indonesian native species and as a key species for ornamental aquaculture. The problem in mass production of this species are the low of growth rate which causes a long period of rearing and low of survival rate. The purpose of the present study was to evaluate free glutamine supplementation at different doses in diet to increase physiological response, growth performance and survival rate of clown loach. Expe-rimental diets contained four different free glutamine levels, viz 0, 1, 2 and 3%. These diets were given to six repli-cate groups of 50 juvenile clown loaches. The fish were reared in each aquarium with dimensions of 40×30×30 cm3 for 60 days. Fish were fed four times a day at satiation. Parameters observed including intestinal glutamine concen-tration, villous and intestinal morphometry, intestinal protease activity, feed efficiency, nutrient retention, growth performance, survival rate, superoxide dismutase (SOD) activity, and malondialdehyde (MDA). The results showed that supplementation of 1% free glutamine significantly affected the morphometry of villi. The length and surface area of villi at a dose of 1% showed the highest values i.e., 320.44 ± 10.39 μm and 27,046.79 ± 250.54 μm2, respect-ively. The 1% dose also had a significant effect on protease activity (13.57 ± 1.92 mg units of protein-1) compared to the 0% dose. The 2% dose showed the highest SOD activity (0.82 ± 0.07 mg protein-1 unit) and the lowest MDA level was found at a dose of 3% (0.25 ± 0.02 nmol mg protein-1). Feed consumption with the supplementation of free glutamine has a significant effect on survival rate with the highest value reached 97.00 ± 1.00%, but no significant effect on intestinal morphometry, feed efficiency, nutrient retention and growth performance. Dietary with the sup-plementation of free glutamine is not able to improve growth performance, but can improve the physiological res-ponse and survival rate.

EVALUASI PENGARUH HORMON GONADOTROPIN PADA TINGKAT KEMATANGAN GONAD IKAN BOTIA (CHROMOBOTIA MACRACANTHUS)

Botia fish (Chrombotia macracanthus), known as the clown loach, is a species of freshwater ornamental fish from the Cobitidae family whose distribution is limited to the islands of Borneo and Sumatra. The limitations of Botia fish distribution make it necessary to increase the maturity of the gonadal Botia fish to increase the breeding of these fish. The results of the evaluation of the effect of gonadotropin hormone on fish Botia carried out for four days and on the first female parent produced as many as 15,898 eggs with FR (Fertilization Rate) of 57.5% and HR (Hatching Rate) of 60.5%. The second Botia parent produces 10,872 eggs with FR (Fertilization Rate) of 96.5% and HR (Hatching Rate) of 13.7%. HCG serves to homogenize the size of the egg and accelerate gonadal maturity. Ovaprim serves to accelerate the ovulation process and stimulate spawning.

Short Communication: Application of artificial reefs for fisheries enhancement in Probolinggo, Indonesia

Abstract. Isroni W, Samara SH, Santanumurti MB. 2019. Short Communication: Application of artificial reefs for fisheries enhancement in Probolinggo, Indonesia. Biodiversitas 20: 2273-2278. Overfishing is one of the biggest challenges in the fisheries sector in Probolinggo, Indonesia. The fish apartment (artificial reefs) was one of the solutions to increase the fish resource since it serves as the habitat for fish to live, spawn, and search for food. In this study, the fish apartment was installed in Probolinggo (Karang Katon and Dringu Beach) from 2017 to 2018. This study showed that five fish species (Caesio cuning, Acanthurus achilles, Acanthurus albipectoralis, Sphyraena jello, and Apagon novemfasciatus) were found in Karang Katon while four species (Chaetodon octofasciatus, Chromobotia macracanthus, Nemipterus japonicas, and Lates calcarifer) lived in Dringu Beach. From a total of 333 fishes, A. achilles was the species with the highest composition level of 51.65% (172) in Karang Katon station. In Dringu Beach station, C. octofasciatus had the highest fish species composition level of 46% (183) from a total of 402 fishes. The diversity index and dominance index in Karang Katon station were low at-1.280 and 0.343, respectively. The diversity index and dominance index in Dringu Beach station were also low at -1.115 and 0.3503. A. achilles had the highest density of 34.4 ind/m3 in Karang Katon station while C. octofasciatus had the highest species density of 36.6 ind/m3 in Dringu Beach Station. From this study, it could be concluded that artificial reefs application enhanced the fisheries in Probolinggo, Indonesia, and help its sustainability.

GROWTH RESPONSE OF CLOWN LOACH (Chromobotia macracanthus Bleeker 1852) JUVENILES IMMERSED IN WATER CONTAINING RECOMBINANT GROWTH HORMONE

The main problem in the culture of clown loach (Chromobotia macracanthus) is the slow growth rate, which takes about six months to reach its market size (two inches total body length). Slow growth eventually cause a long production time and increase the production costs. An alternative solution can be proposed in order to enhance the growth is by using recombinant growth hormone. The aim of this study was to determine the immersion dose of recombinant Epinephelus lanceolatus growth hormone (rElGH) which can generate the highest growth in clown loach. Larvae at seven day after hatching were hyperosmotic treated with NaCl 2.0% for one minute, then immersed for one hour in water containing 0.3% NaCl, 0.01% bovine serum albumin (BSA), and different doses of rElGH, namely: 0.12 (treatment A), 1.2 (B), 12 (C), and 120 mg/L (D). As control, fish were immersed in water without rElGH and NaCl (control-1), water containing 0.3% NaCl and 0.01% BSA (control-2), and 0.3% NaCl water (control-3). Each treatment was replicated three times. The results showed that clown loach juveniles in treatment B, C, and D had longer total body length (P&lt;0.05) than control-1, while fish treatment A was the same as controls. Survival and body weight were similar in all treatments and controls (P&gt;0.05). In addition, the percentage of large size juveniles increased approximately 5% in treatment B, almost the same as in the medium size, while the small size were decrease compared to the control-1. Thus, the best immersion dose of rElGH was 1.2 mg/L water.

Pathogen Inventory of Botia (Chromobotia macracanthus Bleeker) in Fish Quarantine Supadio, Pontianak

Disease was a major obstacle in the cultivation of orrnamental fish, one of them is botia. The many types of diseases that infected botia can cause huge losses. The efforts that could minimize these losses was prevented the spread of disease. The purpose of this study was to determine the types of pathogen that infected botia (Chromobotia macracanthus Bleeker) in fish quarantine Supadio, Pontianak. The observations were identification of parasites, bacteria and fungi. The results showed that the agent of disease affecting botia are Gyrodactylus sp., Myxobolus sp., Argulus sp., Vorticella sp. from parasite agent, Neisseria sp., Aeromonashydrophila, Chromobacterium violaceum, Pasteurella hemolytica from bacteria agent and Saprolegnia sp. from fungi agent. All of agent diseases are not belonged to fish disease quarantine.

Biology and culture of the clown loachChromobotia macracanthus(Cypriniformes, Cobitidae) : 2- Importance of water movement and temperature during egg incubation

In comparison to older life stages, the embryonic stages of fishes generally have narrow tolerance ranges for environmental conditions, as regards water quality, temperature and mechanical shocks. The knowledge of these factors is indispensable to appraise the threats brought about by climate or anthropogenic changes upon their resilience, and to define adequate ways of incubating their eggs for an efficient propagation of the species under controlled conditions. Clown loach eggs have a narrow thermal tolerance range in comparison to other tropical and temperate fishes. Hatching occurs at 22–30 °C, and non-deformed larvae can only be obtained at 23.8–30.2 °C. Furthermore, the thermal tolerance of any particular progeny was found dependent on the maintenance temperature of the female parent, thereby making the actual tolerance no broader than 4.5 °C. The (log-log) relationship between the duration of the incubation period and temperature was characterized by a shallow slope, which is more typical of coldwater fishes, as is a narrow thermal tolerance range. On the other hand, clown loach hatched more rapidly (20 h at 26 °C) than predicted by existing models on the basis of water temperature and egg diameter, a feature that is shared by other warmwater fishes producing eggs that undergo a strong swelling process (about three times the ova diameter in clown loach). Clown loach embryos are strongly sensitive to mechanical shocks, but their development is not viable either in protracted steady state conditions, in absence of water movement, as they develop various deformities (e.g. pericardial oedema). This is thought to originate from a hypoxic microenvironment around the embryo, as a consequence of an oxygen gradient developing inside and outside the egg, since the boundary diffusion layer is not refreshed by water movement. This issue is worsened by strong egg swelling and incubation at warm temperature.

Biology and culture of the clown loachChromobotia macracanthus(Cypriniformes, Cobitidae) : 4- Thermal biology of embryos and larvae

The knowledge of how fish survive and grow at different temperatures, and how these traits vary between life stages, is essential to evaluate the effects of climate change on wild fish and implement effective strategies in aqua- culture. These issues are addressed in this study through a series of experiments that evaluate the effect of temperature (23−34 ◦ C) on the embryos and larvae of clown loach, Chromobotia macracanthus. This species is endemic to the rivers of Sumatra and Borneo, highly praised on the ornamental fish market, and has been reproduced in captivity recently. No embryo survived a 24-h exposure to 34 ◦ C until the age of 3 days after hatching (dah); mortality was high at 32 ◦ C at 2 and 3 dah, whereas it was low and similar from 1 to 4 dah at 23−29 ◦ C( <10%). Yolk absorption was proportional to water temperature (Q10 ◦C of 1.69 in the 23−32 ◦ C range), but fish reared at cold temperatures were larger than others at the start of exogenous feeding (5.7 vs. 5.5 mm TL, at 23 and 32 ◦ C, respectively). The survival of larvae fed Artemia nauplii ad libitum was high at 23−32 ◦ C( 80 −100%), but almost null at 34 ◦ C. Growth models at different tempera- tures were produced from weekly measurements in two experiments, and tested by comparing their predictions with the results of a third experiment. Throughout the larval stage, the optimal temperature for growth (T ◦) was close to 29 ◦ C, and departures from T ◦ resulted in substantial growth penalties (−30% SGR for -5.1 ◦ Ca nd+3.1 ◦ C). High survival, fast growth (0.7 mm day −1 ) and limited size dispersal at T ◦ opt are encouraging perspectives for the aquaculture of clown loach. From an ecological perspective, the species has an atypical thermal biology, as it is less thermophilic than other tropical fishes, but more stenothermal than temperate fishes exhibiting similar values of T ◦ opt, both traits being of particular concern in the context of global warming.

Biology and culture of the clown loachChromobotia macracanthus(Cypriniformes, Cobitidae) : 1- Hormonal induced breeding, unusual latency response and egg production in two populations from Sumatra and Borneo Islands

The clown loach Chromobotia macracanthus, endemic to Indonesia, is a major species on the international market of ornamental freshwater fish. In order to satisfy an increasing demand with a sustainable alternative to the massive capture of wild juveniles, research has been dedicated to the artificial propagation and domestication of this species. The present study, the first of a series, focused on favourable maintenance conditions for broodfish sexual mat- uration, criteria for identification of ripe fish, efficiency of hormone-induced breeding treatments, predictability of their latency response, and on the comparison of reproductive performances of fish from populations of Sumatra and Borneo Islands (in total, 112 females of 46 to 404 g body weight). When reared in fully controlled conditions in large water recirculation systems, broodfish originating from Sumatra had reproductive performances similar to or slightly higher than those maturing in the wild (ovulation rate of 93% vs. 82%, relative fecundity of 109 277 vs. 103 550 ova kg −1 and fertilization rate of 73% vs. 61%, respectively). In the same rearing conditions, captive females from Borneo (n = 22) showed lower ovulation rate (77%), relative fecundity (76 262 ova kg −1 ) and fertilization rate (50%) than those originat- ing from Sumatra (n = 28). By contrast, the mean individual weight of ova (around 0.8 mg) was independent from the origin or maintenance conditions of females. An initial modal follicle diameter ≥1.02 mm generally led to high ovula- tion success (>80%) after hormonal treatment and is recommended as the main criterion for selecting female broodfish. Two hormonal treatments for inducing oocyte maturation and ovulation (T1: two successive injections of Ovaprim at a 6 h-interval; T2: one injection of human chorionic gonadotropin (hCG)- and one of Ovaprim 24 h later), produced sim- ilar results in terms of ovulation rate, quantity and quality of ova collected. With both treatments, the latency decreased with increasing water temperature, then increased again at temperatures >28−29 ◦ C. To our knowledge, such U-shaped relationship between the latency response and temperature has never been documented in teleost fishes.

Biology and culture of the clown loachChromobotia macracanthus(Cypriniformes, Cobitidae) : 3- Ontogeny, ecological and aquacultural implications

Hatchlings of clown loach (3.8 mm in total length, TL ) are pelagic. When reared at 26−28 °C, they become benthic 3 days after hatching (dah), when their swim bladder is inflated. The fin development sequence (pectorals , but the finfold persists until 25 − 26 mm TL (start of juvenile stage). Melanophores appear at 3 dah, they form a 5-bar pattern at 5 dah, then two bars (III and V) vanish progressively, producing at 26 mm TL the 3-bar pattern that is typical of adults. Throughout the ontogeny, the pigment pattern exhibits a structural regularity (bars spaced at regular intervals), which is interpreted in a functional perspective by reference to the maintaining of crypsis and signalling throughout. Exogenous feeding commences at 4 dah (5.5 mm TL ). Food intake (FI ) increases rapidly, from 6% wet body mass (WM ) at 5.5 mm TL to >20% WM in fish > 7 mm TL . Gut evacuation rate (R g ) increases with increasing meal size and fish size, as a result of gut coiling (from 8 to 15 mm TL ), and is highest at 11 mm TL (about 10% WM h-1 in fish feeding maximally). The allometric increase of FI and R g during the early larval stages is accompanied by increasing capacities for growth, so early sizes differences amplify rapidly during the ontogeny. Nevertheless, growth remains slow (mean of 0.4 mm TL day-1 from 4 to 29 dah; 0.9 mm TL day-1 for top growers). By contrast, unfed fish display long resistance to starvation (until 14−15 dah). The combination of slow growth and long resistance to starvation is discussed in respect to the reproductive phenology of the species, as the capacity of making metabolic economies prevails over fast growth for seasonal strategists spawning mainly at the start of the rainy season.

THE UTILIZATION OF THE KINDS OF LIVE FOOD ON CLOWN LOACH FISH JUVENILES (Chromobotia macracanthus Bleeker)

Domestication and mass production technology of clown loaches fish have been developed by the Research Institute for Ornamental Fish Culture, Depok and the Institute de Recherche pour le Developpement (IRD). In the process, some constraints has been found and one of them was the cost of production and sustainable supply of Artemia as the only one of live food which used for clown loaches post-larvae until 2-3 months old juvenile. To solve this constraints, the use of other live feed as a substitute or replacement of Artemia should be applied, caused by it research of the utilization of the kinds of live food on clown loach juvenile need to be done. This research aims to determine the kinds of live food which be recommended for the substitution of Artemia on clown loaches fish juvenile (Chromobotia macracanthus Bleeker). Research carried out using 1 month old clown loach juveniles designed into the Complete Randomized Design in two factors namely are class of fish size S (35-50 mg), M (55-70 mg), L (75-90 mg) and the kinds of live food in the form of Artemia as a control, Moina, mini maggot, blood worms (Chironomus), and silk worms (Tubifex). Three levels treatment by class of fish size factor and five levels treatment by the kinds of live food factor produce 15 kinds of interactions with duplications. The research was conducted at recirculation system for 8 weeks to 3 months old juveniles. Observations were carried and measuring the growth parameters including weight, total length of fish, as well as survival rate parameters based on the number of fish that live at the end of the research. The support is done by measuring the water quality of pH, DO, temperature, ammonia, conductivity, and nitrites, proximate analysis of feed also performed. The two of research step analyzed by ANOVA (Analysis of Variance) and continued by Tukey test.

The Rearing of Clown Loach (Chromobotia macracanthus) Larvae by Using Enriched Live Foods

&lt;p&gt;The enrichment of natural live food with unsaturated fatty acid can increase survival and growth rate of fish larvae. The purpose of this experiment was to know the effect of various natural live food with or without nutrient enrichment on survival and growth rate of clown loach (&lt;em&gt;Chromobotia macracanthus&lt;/em&gt;) larvae. The experiment was done indoor by using plastic jars filled 5 L water and aerated continuously. Twenty clown loach larvae of four days old, 5.58 ± 0.12 mm in average length, were stocked in plastic jars and were reared for 28 days. The treatment were: a) &lt;em&gt;Artemia&lt;/em&gt; nauplii as control; b) rotifer without enrichment; c) enriched rotifer, d) &lt;em&gt;Moina&lt;/em&gt; nauplii without enrichment, and e) enriched &lt;em&gt;Moina&lt;/em&gt; nauplii. As enrichment agent, we used 200 mg of tuna eggs powder and 200 mg of baker's yeast which dissolved and aerated in 2 L of water for one hour. Proximate analysis for amino and fatty acids content were done before the treatment, at 5 days old and at 32 days old (juvenile). The result showed that higher survival (80.00%) and growth rate (average body length 12.80±1.85 mm) could be achieved by feeding clown loach larvae with enriched &lt;em&gt;Moina&lt;/em&gt; nauplii.&lt;/p&gt; &lt;p&gt;Keywords: clown loach larvae, live feed, nutrient enrichment&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;ABSTRAK&lt;/p&gt; &lt;p&gt;Pengkayaan asam lemak tak jenuh dari pakan hidup dapat meningkatkan sintasan dan pertumbuhan larva ikan. Penelitian dilakukan bertujuan untuk mengetahui pengaruh pakan hidup dengan atau tanpa diperkaya nutrisinya terhadap sintasan dan pertumbuhan larva ikan botia (&lt;em&gt;Chromobotia macracanthus&lt;/em&gt;). Penelitian dilaksanakan di dalam ruangan tertutup menggunakan wadah plastik yang berisi media air 5 L serta diaerasi terus menerus. Larva umur empat hari dengan panjang rata-rata 5,58 ± 0,12 mm ditebar sebanyak 20 ekor per wadah. Pemeliharaan larva dilakukan selama 28 hari. Perlakuan perbedaan jenis pakan hidup dengan atau tanpa diperkaya, yaitu : a) naplii&lt;em&gt; Artemia&lt;/em&gt; (kontrol), b) rotifer tanpa diperkaya nutrisinya, c) rotifer diperkaya nutrisinya, d) nauplii &lt;em&gt;Moina&lt;/em&gt; tanpa diperkaya nutrisinya dan e) nauplii&lt;em&gt; Moina&lt;/em&gt; diperkaya nutrisinya. Pengkayaan pakan alami menggunakan tepung telur tuna dan ragi roti masing-masing 200 mg dalam 2 L media air yang diaerasi selama 1 jam. Analisis proksimat, asam amino dan asam lemak pakan alami dan larva umur empat hari dilakukan sebelum penelitian dan juvenil botia 32 hari dianalisis pula. Hasil penelitian menunjukkan bahwa sintasan (80,00%) dan pertumbuhan (panjang mutlak 12,90 ± 1,85 mm) yang tinggi dapat diperoleh dengan memberikan nauplii &lt;em&gt;Moina&lt;/em&gt; yang diperkaya pada larva botia&lt;/p&gt; &lt;p&gt;Kata kunci: larva ikan botia, pakan alami, pengkayaan nutrisi&lt;/p&gt;