Multi-omic characterization of the thermal stress phenome in the stony coral Montipora capitata

Background Corals, which form the foundation of biodiverse reef ecosystems, are under threat from warming oceans. Reefs provide essential ecological services, including food, income from tourism, nutrient cycling, waste removal, and the absorption of wave energy to mitigate erosion. Here, we studied the coral thermal stress response using network methods to analyze transcriptomic and polar metabolomic data generated from the Hawaiian rice coral Montipora capitata. Coral nubbins were exposed to ambient or thermal stress conditions over a 5-week period, coinciding with a mass spawning event of this species. The major goal of our study was to expand the inventory of thermal stress-related genes and metabolites present in M. capitata and to study gene-metabolite interactions. These interactions provide the foundation for functional or genetic analysis of key coral genes as well as provide potentially diagnostic markers of pre-bleaching stress. A secondary goal of our study was to analyze the accumulation of sex hormones prior to and during mass spawning to understand how thermal stress may impact reproductive success in M. capitata. Methods M. capitata was exposed to thermal stress during its spawning cycle over the course of 5 weeks, during which time transcriptomic and polar metabolomic data were collected. We analyzed these data streams individually, and then integrated both data sets using MAGI (Metabolite Annotation and Gene Integration) to investigate molecular transitions and biochemical reactions. Results Our results reveal the complexity of the thermal stress phenome in M. capitata, which includes many genes involved in redox regulation, biomineralization, and reproduction. The size and number of modules in the gene co-expression networks expanded from the initial stress response to the onset of bleaching. The later stages involved the suppression of metabolite transport by the coral host, including a variety of sodium-coupled transporters and a putative ammonium transporter, possibly as a response to reduction in algal productivity. The gene-metabolite integration data suggest that thermal treatment results in the activation of animal redox stress pathways involved in quenching molecular oxygen to prevent an overabundance of reactive oxygen species. Lastly, evidence that thermal stress affects reproductive activity was provided by the downregulation of CYP-like genes and the irregular production of sex hormones during the mass spawning cycle. Overall, redox regulation and metabolite transport are key components of the coral animal thermal stress phenome. Mass spawning was highly attenuated under thermal stress, suggesting that global climate change may negatively impact reproductive behavior in this species.

Reproductive biology of the anchovy (Stolephorus commersonnii, Lacepède, 1803) and spotted sardine (Amblygaster sirm, Walbaum, 1792) from Tanga Region, Tanzania

The present study investigated the reproductive biology of Stolephorus commersonnii and Amblygaster sirm at two landing sites in Tanga on the northern coast of Tanzania. Fish samples were collected on a monthly basis from ringnets operated by artisanal fishers in the nearby coastal waters. Spawning seasons were determined using gonadosomatic index (GSI) and gonadal maturity stages. The size at first maturity was 57.7 mm and 66.2 mm total length for male and female S. commersonnii respectively. Male and female A. sirm were estimated to attain first maturity at 147.7 mm and 169.2 mm respectively. The spawning seasons of both species were protracted. S. commersonnii demonstrated a year round spawning cycle with peaks in August, October and January. The peak spawning season for male and female A. sirm was recorded in August and September respectively. Both species exhibited skewed size-dependent sex ratios with females predominating in the larger size classes. A. sirm had a higher fecundity rate with a maximum of 96,500 eggs in the largest female fish of 258 mm as compared to S. commersonnii (10,055 eggs) in the largest fish of 98 mm. The mean (±SE) total fecundity of S. comersonnii and A. sirm was 5,134.7 ± 136.9 eggs, and 47,029.03 ± 1,435.13 eggs in females of sizes 68 mm to 98 mm and 170 mm to 258 mm respectively.

Masculinization of Banggai Cardinalfish (Pterapogon kauderni) using 17α-Methyltestosterone-enriched Artemia sp.

Banggai Cardinalfish (Pterapogon kauderni) is one of the endemic fish from the waters of the Banggai Islands, Central Sulawesi Province. One factor challenging the production of P. kauderni larvae is the male fish will nurture the eggs and larvae for 30 days, hindering next spawning cycle. One effort to overcome this problem an increase of male fish number should be performed, for example through sex reversal. This study aimed to determine the effectiveness of the hormone 17α-methyltestosterone (17α-MT) through Artemia sp. to increase male sex percentage P. kauderni. This study used a completely randomized design by testing four treatments namely feeding Artemia sp. which has been soaked with 2.0 mg of the 17α-MT hormone for two- hours given to P. kauderni larvae for 10 days (A); 20 days (B); 30 days (C), and without hormone treatment 17α-MT (control). Each treatment included control was performed in triplicates. The percentage of male sex was 93.33 % at 30 days treatment and was higher (P<0.05) compared to controls (53.3 %). Additionally, the results showed that daily growth rate, biomass gain and survival rate of all treatments were not significantly different (P>0.05) with those of control. In conclusion, Artemia sp. contained 17α-methyltestosterone enhanced male percentage of P. kaurderni. Keywords: growth, male percentage, Artemia sp., survival rate, Pterapogon kauderni

Rekayasa Rematurasi Ikan Koki Oranda (Carassius sp.) Menggunakan Hormon Oodev Pada Dosis Yang Berbeda

Oranda chef fish is a type of goldfish that has a round body with a small head and a broad tail. This fish comes from mainland china, but in Indonesia has long been able to be cultivated. The prospect of maintaining ori chef fish is quite promising because for marketing in addition to the target in the country is also a type of fish in the export and the price is quite high. Oranda Chef Fish has some favorable properties to be cultivated for example the relatively high price of spawning cycle is relatively shorter. The purpose of the other researchers Knowing how to accelerate the maturity of the gonad chef oranda using hormones Oodev with different doses. Know the effect of Oodev hormone on remediation of ori chef fish. Know the dosage of OODev hormone effective for remandasi fish chef oranda This study used an experimental method with Completely Randomized Design (RAL) consisting of 4 treatments in which the first treatment of prospective parent who was not given Oodev hormone or as control, treatment of the two candidate mothers given a dose of 0.5 mL / kg hormone, treatment of the three prospective mothers With a dose of 1 mL / kg and the last treatment where the prospective parent with a dose of 1.5 mL / kg. Each treatment was repeated 3 times each. With 8 test parameters namely; Index gonad maturity, histology gonad, fekuenditas, egg diameter, degree of egg fertilization, degree of egg penetration, larval larva and water quality. And using ANOVA Statistic Analysis data analysis tool. Based on the results of the research of all parameters Test that the dose of 1 mL / kg is the dominant dose and most effective for maturity of the parent candidate gonad and larval life rate.