Effect of type and concentration of antioxidant on sperm motility, viability, and DNA integrity of climbing perch Anabas testudineus Bloch, 1792 (Pisces: Anabantidae) post-cryopreservation

Sperm quality is preserved through the crucial involvement of antioxidants, which play a vital role in minimizing the occurrence of reactive oxygen species (ROS) during the cryopreservation process. The suitability of the type and concentration of antioxidants are species-dependent, and this study is crucial in order to improve the quality of the climbing perch sperm post-cryopreservation. Therefore, this study aimed to determine the best type and concentration of antioxidants for cryopreservation of climbing perch Anabas testudineus sperm. To achieve this, 6 types of antioxidants, namely, ascorbic acid, beta-carotene, glutathione, butylated hydroxytoluene (BHT), myo-inositol, and alpha-tocopherol, with inclusion of a control were tested in 3 replications at three concentration levels of 0 mg/L (control), 20 mg/L, 40 mg/L, and 60 mg/L. Sperm was diluted in a glucose-base extender at a ratio of 1:60 (sperm: glucose base), then 10 % DMSO and 5 % egg yolk was added before cryopreservation for two weeks. The results showed that the type and concentration of antioxidants had a significant effect on the motility and viability of cryopreserved climbing perch sperm (P < 0.05), where the best results for ascorbic acid, beta-carotene, glutathione, myo-inositol, and alpha-tocopherol were obtained at a concentration of 60 mg/L, while BHT was at a concentration of 20 mg/L. The best results for glutathione, myo-inositol, and alpha-tocopherol were significantly different from other treatments, while the best results for ascorbic acid and beta-carotene (60 mg/L) were not significantly different from the 40 mg/L concentration, while the best results for BHT were not significantly different from the control treatments. Therefore, the best concentration of glutathione, myo-inositol, and alpha-tocopherol was 60 mg/L, while for ascorbic acid and beta-carotene it was 40 mg/L, and BHT was not recommended. DNA integrity analysis indicated the absence of fragmentation in all samples, including fresh, control, and treated sperm. Based on practical and economic considerations, myo-inositol at 60 mg/L was recommended for cryopreservation of climbing perch A. testudineus sperm.

Macroalgae exhibit diverse responses to human disturbances on coral reefs

Scientists and managers rely on indicator taxa such as coral and macroalgal cover to evaluate the effects of human disturbance on coral reefs, often assuming a universally positive relationship between local human disturbance and macroalgae. Despite evidence that macroalgae respond to local stressors in diverse ways, there have been few efforts to evaluate relationships between specific macroalgae taxa and local human-driven disturbance. Using genus-level monitoring data from 1205 sites in the Indian and Pacific Oceans, we assess whether macroalgae percent cover correlates with local human disturbance while accounting for factors that could obscure or confound relationships. Assessing macroalgae at genus level revealed that no genera were positively correlated with all human disturbance metrics. Instead, we found relationships between the division or genera of algae and specific human disturbances that were not detectable when pooling taxa into a single functional category, which is common to many analyses. The convention to use percent cover of macroalgae as an indication of local human disturbance therefore likely obscures signatures of local anthropogenic threats to reefs. Our limited understanding of relationships between human disturbance, macroalgae taxa, and their responses to human disturbances impedes the ability to diagnose and respond appropriately to these threats.

Effect of type and concentration of cryoprotectant on the motility, viability, and fertility of climbing perch Anabas testudineus Bloch, 1792 (Pisces: Anabantidae) sperm

The climbing perch, Anabas testudineus is a freshwater fish that has economic value in Indonesia. It is cultured in the country, but the breeding technology, specifically sperm storage, is not well developed. Sperm cryopreservation is one of the preservation methods that need to be developed to support fish breeding technology. The type of cryoprotectants and its concentration are species-dependent and determines the success of this approach. Therefore, this study is aimed at determining the optimal type and concentration of cryoprotectant for sperm cryopreservation of A. testudineus. Four separate study series were performed, each of which evaluated one type of cryoprotectant at five concentration levels. The cryoprotectants used were DMSO, methanol, glycerol, and ethanol, and the tested concentrations were 0%, 5%, 10%, 15%, and 20%, which were combined with 5% egg yolks. Each treatment was conducted with three replications. The results showed that the type of cryoprotectant and its concentration significantly affected sperm motility, viability, and fertility of climbing perch (P < 0.05). The best outcome was obtained in DMSO, and methanol at a concentration of 10%, glycerol at 5%, and ethanol at 15%. However, the highest motility, viability, and fertility values were observed at 10% DMSO, indicating it is the best type and concentration for sperm cryopreservation of climbing perch A. testudineus.

Improvement of Sperm Quality of the Depik Fish, Rasbora tawarensis, After Cryopreservation Using Antioxidant

BACKGROUND: The cryopreservation of the sperm of the depik fish, Rasbora tawarensis, has previously been developed. However, the quality of the sperm post cryopreservation was not satisfactory and might be improved through the application of antioxidants. OBJECTIVE: To determine the most suitable antioxidant for the cryopreservation of the depik fish spermatozoa. MATERIALS AND METHODS: A completely randomized design with a non-factorial experiment was used and the tested antioxidants were glutathione, β-carotene, ascorbic acid, and butylated hydroxytoluene (BHT) at 6% concentrations. All treatments had three replications. The sperms were collected from 10 male fishes and diluted with Ringer solution in a ratio of 1: 20 (v/v, sperm: Ringer solution). Then 5% DMSO and 5% egg yolk were added to the diluted sperms. Furthermore, 6% of the tested antioxidants were added to the diluents, and then, cryopreservation was carried out in liquid nitrogen for 14 days. RESULTS: The ANOVA test showed that the application of antioxidants significantly affected the sperm motility, fertility, and hatching rates of the eggs (P> 0.05). Furthermore, the antioxidants also protected the sperm cells during cryopreservation, with glutathione being the best antioxidant. CONCLUSION: The application of antioxidants during the cryopreservation of depik fish sperm had a significant effect on motility, fertility and hatchability of eggs post-cryo. Furthermore, glutathione was the most suitable antioxidant.

Lernaea cyprinacea Linnaeus, 1758 (Copepoda: Lernaeidae) infection on Betta rubra Perugia, 1893 (Anabantiformes: Osphronemidae) from Aceh Province, Indonesia

Betta rubra is an ornamental freshwater fish endemic to northern Sumatra, Indonesia. The B. rubra population has decreased in recent decades, and is classified as an endangered species in the IUCN Red List. This study aims to report for the first time infection by L. cyprinacea in B. rubra harvested from the Aceh Besar region of Indonesia. The fish samples were obtained from the Cot Bira tributaries, Aceh Besar District, Indonesia from January to December 2020. The results showed that the parasite infected 6 out of 499 samples in August and September, with a prevalence and intensity rate of 1% and 2 parasites/fish, respectively. The eyes and pectoral fins were the common infection sites. Despite B. rubra is not an optimal host (small size) for the parasite, this parasite might serve as additional threatening factors for the endangered B. rubra fish population.

Effect of cryoprotectant on the motility, viability, fertilization, and DNA integrity of naleh fish Barbonymus sp. (Cyprinidae) sperm

Naleh fish Barbonymus sp. is a commercial freshwater fish, which is indigenous to Aceh, Indonesia. The population of this species has declined over the years as a result of habitat perturbations and overfishing. Hence, the crucial need to develop a cryopreservation method to support breeding programs. This involved the use of a cryoprotectant as an important component. The objective of this study, therefore, was to explore the best cryoprotectant for naleh fish spermatozoa, and a total of five types were tested. These include the DMSO, Methanol, Ethanol, Glycerol, and Ethylene Glycol at a similar concentration of 10%, which were individually combined with 15% egg yolk, and every treatment was performed in three replications. Conversely, Ringer’s solution was adopted as an extender, and the sperm was cryopreserved in liquid nitrogen for 15 days. The results showed significant influence on sperm motility and viability, as well as egg fertility of naleh fish (P <0.05), although the DMSO provided the best outcome, compared to others at 47.17%, 50.13%, and 45.67%, respectively. Furthermore, DNA fragmentation had not occurred in the fresh and cryopreserved sperm samples, indicating the protective effect of tested cryoprotectants. It is concluded that the 10% DMSO and 15% egg yolk is the best cryoprotectant for naleh fish spermatozoa.

An Indo-Pacific coral spawning database

The discovery of multi-species synchronous spawning of scleractinian corals on the Great Barrier Reef in the 1980s stimulated an extraordinary effort to document spawning times in other parts of the globe. Unfortunately, most of these data remain unpublished which limits our understanding of regional and global reproductive patterns. The Coral Spawning Database (CSD) collates much of these disparate data into a single place. The CSD includes 6178 observations (3085 of which were unpublished) of the time or day of spawning for over 300 scleractinian species in 61 genera from 101 sites in the Indo-Pacific. The goal of the CSD is to provide open access to coral spawning data to accelerate our understanding of coral reproductive biology and to provide a baseline against which to evaluate any future changes in reproductive phenology.

DNA barcoding of commercially important reef fishes in Weh Island, Aceh, Indonesia

Knowledge on the precise identification of fish resources is critical for sustainable fisheries management. This study employs the DNA barcoding approach to generate a molecular taxonomic catalogue of commercially important reef fishes in the waters of Weh Island (Aceh Province), the most northerly inhabited island in the biodiverse Indonesian Archipelago. The waters not only support artisanal fisheries but also a feeder for the industry in the greater island of Aceh. In total, 230 specimens from 72 species belonging to 32 genera and 17 families were DNA barcoded, representing a major segment of the captured reef fish taxa and a quarter of fish species diversity that had previously been recorded. The sequence read lengths were 639 bp revealing 359 conserved sites, 280 variable sites, 269 parsimony informative and 11 singletons. Our molecular findings paralleled the morphological identification with no evidence of cryptic species or new species discovery. This study is a significant contribution to the fisheries statistics of this area, which would facilitate assessment of species catch composition and hence for strategizing management plans. It is an important input to the DNA barcode library of Indonesian marine fishes and to the global DNA barcode entries in general.

Data of feed formulation for Indonesian short-fin eel, Anguilla bicolor McClelland, 1844 elver

This article describes the data of raw material compositions for formulating the diet for Indonesian short-fin eel, Anguilla bicolor Anguilla bicolor McClelland, 1844 elver. The data on growth performance, survival and feed utilization of eel elver from the formulated diet test results are also presented here. Four formulated diets and one commercial feed were tested for the eel elver. The formulated diet was formulated from animal and plant based protein sources such as; fish meal, cornmeal, soybean meal, fine bran, ebi-shrimp meal, golden snail meal, bloodmeal, and tapioca flour. Vitamins and minerals were added into the diet. In addition, probiotics and papain enzyme and its combination were also included into the experimental diets to boost the growth performance, survival and feed utilization of the fish. The tested treatments were; (A) commercial diet without probiotic and papain enzyme, (B) experimental diet without probiotic and papain enzyme, (C) experimental diet with probiotic 10 ml kg⁻¹ feed, (D) experimental diet with papain enzyme 10 g kg⁻¹ feed, (E) experimental diet with probiotic 10 ml kg⁻¹ + papain 10 g kg⁻¹ feed, (F) experimental diet with probiotic 5 ml kg⁻¹ + papain 5 g kg⁻¹ feed. Each experimental fish group was fed on an experimental diet twice a day at 08.00 AM and 06.00 PM at feeding level of 10% body weight for 60 days. The results showed that the weight gain ranged between 4.60 g to 5.92 g, daily growth rate between 0.063 g day⁻¹ and 0.098 g per day⁻¹, the specific growth rate varies from 0.72% day⁻¹ to 1.35% day⁻¹, survival rate 50.00% to 73.33%, feed conversion ratio from 2.35 to 4.17, and feed efficiency between 41.82% to 58.98%. The best treatment was found in fish fed on the experimental diet with papain enzyme 10 g kg⁻¹ of feed

Assessing the species composition of tropical eels (Anguillidae) in Aceh Waters, Indonesia, with DNA barcoding gene cox1

The objective of the present study was to evaluate the species diversity of eels native to Aceh waters based on genetic data. Sampling was conducted in western coast waters of Aceh Province, Indonesia, from July to August 2016. Genomic DNA was extracted from the samples, a genomic region from the 5’ region of the cox1 gene was amplified and sequenced, and this was then used to analyse genetic variation. The genetic sequences were blasted into the NCBI database. Based on this analysis there were three valid species of eels that occurred in Aceh waters, namely Anguilla marmorata, A. bicolor bicolor, and A. bengalensis bengalensis.

Growth performance and feed utilization of keureling fish Tor tambra (Cyprinidae) fed formulated diet supplemented with enhanced probiotic

Background The objective of the present study was to determine the optimum dosage of probiotic in the diet of keureling fish ( Tor tambra) fry. MethodsLactobacillus casei from Yakult® was used as a starter, and enhanced with Curcuma xanthorrhiza, Kaempferia galanga and molasses. The mixture was fermented for 7 days prior to use as probiotic in a formulated diet containing 30% crude protein. Four levels of probiotic dosage; 0 ml kg -1 (control), 5 ml kg -1, 10 ml kg -1 and 15 ml kg -1 were tested in this study. The fish was fed twice a day at 08.00 AM and 06.00 PM at the ration of 5% body weight for 80 days. Results The results showed that growth performance and feed efficiency increased with increasing probiotic dosage in the diet from control (no probiotic) to 10 ml kg -1 of probiotic dosage and then decreased when the dosage was increased up to 15 ml kg -1. Conclusions The best values for all measured parameters were recorded at the dosage of 10 ml kg -1. Therefore, it was concluded that the optimum dosage of enhanced probiotic for T. tambra fry was 10 ml kg -1 of feed.

The Effectiveness of Experimental Diet with Varying Levels of Papain on The Growth Performance, Survival Rate and Feed Utilization of Keureling Fish (Tor tambra)

<p>The objective of present study was to determine the optimum level of papain in the diet of <em>keureling </em>fish (<em>Tor tambra</em>). The complete random design was utilized in this study. Six levels of papain dosage were tested in triplicates, i.e. 0 (control); 17.5 mg kg^-1,  20.0 mg kg^-1, 22.5 mg kg^-1, 25.0 mg kg^-1 and 27.5 mg kg^-1 of feed. The experimental fish were fed the experimental diet two times a day at 8 AM and 5 PM at feeding level of 5% body weight for 90 days. The Anova test result showed that papain enzyme  gave a significant effect on the weight gain, daily growth rate, specific growth rate, survival rate, feed conversion ratio and feed efficiency (P&lt;0.05). The Duncan multi-rage test result showed that the higher values for all measured parameters were obtained at the dosage of 27.5 mg kg^-1. Therefore, it is concluded that the optimum dosage of papain enzyme for <em>keureling</em> fish was 27.5 mg kg^-1of feed.</p>

Ichthyofauna of Tripa Peat Swamp Forest, Aceh province, Indonesia

The Tripa Peat Swamp Forest (TPSF) suffers from deforestation due to agriculture, this habitat degradation potentially has a negative impact on fish biodiversity and community assemblages. The objective of this study was to develop an inventory of the fish fauna, evaluate the spatial variation in assemblage structure, document alien species, and quantify the economic value of fish species found from the area. Fish assemblages from the main rivers and tributaries of TPSF were sampled on May to June 2013. A total of 764 individuals were sampled during the survey, constituting 34 families, 47 genera, and 73 species where 46 species are categorized as fish consumption, 17 have potential for aquaculture, and 10 species have potential for ornamental, and three are non native. Cyprinidae is the predominant fish family within the TPSF. Fish assemblages were generally characterized by small population size for each species and low similarity among sites, reflecting the distinctive nature of each sampling site.

Depth-dependent mortality of reef corals following a severe bleaching event: implications for thermal refuges and population recovery

Coral bleaching caused by rising sea temperature is a primary cause of coral reef degradation. However, bleaching patterns often show significant spatial variability, therefore identifying locations where local conditions may provide thermal refuges is a high conservation priority. Coral bleaching mortality often diminishes with increasing depth, but clear depth zonation of coral communities and putative limited overlap in species composition between deep and shallow reef habitats has led to the conclusion that deeper reef habitats will provide limited refuge from bleaching for most species. Here, we show that coral mortality following a severe bleaching event diminished sharply with depth. Bleaching-induced mortality of Acropora was approximately 90% at 0-2m, 60% at 3-4 m, yet at 6-8m there was negligible mortality. Importantly, at least two-thirds of the shallow-water (2-3 m) Acropora assemblage had a depth range that straddled the transition from high to low mortality. Cold-water upwelling may have contributed to the lower mortality observed in all but the shallowest depths. Our results demonstrate that, in this instance, depth provided a refuge for individuals from a high proportion of species in this Acropora-dominated assemblage. The persistence of deeper populations may provide a critical source of propagules to assist recovery of adjacent shallow-water reefs.

Depth-dependent mortality of reef corals following a severe bleaching event: implications for thermal refuges and population recovery

Coral bleaching caused by rising sea temperature is a primary cause of coral reef degradation. However, bleaching patterns often show significant spatial variability, therefore identifying locations where local conditions may provide thermal refuges is a high conservation priority. Coral bleaching mortality often diminishes with increasing depth, but clear depth zonation of coral communities and putative limited overlap in species composition between deep and shallow reef habitats has led to the conclusion that deeper reef habitats will provide limited refuge from bleaching for most species. Here, we show that coral mortality following a severe bleaching event diminished sharply with depth. Bleaching-induced mortality of Acropora was approximately 90% at 0-2m, 60% at 3-4 m, yet at 6-8m there was negligible mortality. Importantly, at least two-thirds of the shallow-water (2-3 m) Acropora assemblage had a depth range that straddled the transition from high to low mortality. Cold-water upwelling may have contributed to the lower mortality observed in all but the shallowest depths. Our results demonstrate that, in this instance, depth provided a refuge for individuals from a high proportion of species in this Acropora-dominated assemblage. The persistence of deeper populations may provide a critical source of propagules to assist recovery of adjacent shallow-water reefs.

Depth-dependent mortality of reef corals following a severe bleaching event: implications for thermal refuges and population recovery

Coral bleaching caused by rising sea temperature is a primary cause of coral reef degradation. However, bleaching patterns often show significant spatial variability, therefore identifying locations where local conditions may provide thermal refuges is a high conservation priority. Coral bleaching mortality often diminishes with increasing depth, but clear depth zonation of coral communities and putative limited overlap in species composition between deep and shallow reef habitats has led to the conclusion that deeper reef habitats will provide limited refuge from bleaching for most species. Here, we show that coral mortality following a severe bleaching event diminished sharply with depth. Bleaching-induced mortality of Acropora was approximately 90% at 0-2m, 60% at 3-4 m, yet at 6-8m there was negligible mortality. Importantly, at least two-thirds of the shallow-water (2-3 m) Acropora assemblage had a depth range that straddled the transition from high to low mortality. Cold-water upwelling may have contributed to the lower mortality observed in all but the shallowest depths. Our results demonstrate that, in this instance, depth provided a refuge for individuals from a high proportion of species in this Acropora-dominated assemblage. The persistence of deeper populations may provide a critical source of propagules to assist recovery of adjacent shallow-water reefs.

Acehnese Reefs in the Wake of the Asian Tsunami

The Sumatra-Andanaman tsunami was one of the greatest natural disasters in recorded human history. Here, we show that on the northwest coast of Aceh, Indonesia, where the tsunami was most ferocious, the damage to corals, although occasionally spectacular, was surprisingly limited. We detected no change in shallow coral assemblages between March 2003 and March 2005, with the exception of one site smothered by sediment. Direct tsunami damage was dependent on habitat and largely restricted to corals growing in unconsolidated substrata, a feature unique to tsunami disturbance. Reef condition, however, varied widely within the region and was clearly correlated with human impacts prior to the tsunami. Where fishing has been controlled, coral cover was high. In contrast, reefs exposed to destructive fishing had low coral cover and high algal cover, a phase shift the tsunami may exacerbate with an influx of sediments and nutrients. Healthy reefs did not mitigate the damage on land. Inundation distance was largely determined by wave height and coastal topography. We conclude that although chronic human misuse has been much more destructive to reefs in Aceh than this rare natural disturbance, human modification of the reef did not contribute to the magnitude of damage on land.