Biofloc technology (BFT) is an alternative aquaculture practice that involves the manipulation of carbon-nitrogen ratio (C:N) to manage nitrogenous waste through microbial assimilation. This study aimed to determine the composition of the microbial community present in BFT and describe the microbial community’s response to C:N manipulation. The experiment had a complete randomized design with two set-ups (i.e., BFT and control) in triplicates. The experimental unit was a 120-L rectangular tank stocked with 15 mixed-sex tilapia fish, Oreochromis niloticus, with an average weight of 15±3 g. The C:N was adjusted to 16:1 using molasses. Illumina MiSeq sequencing platform was used, and bioinformatics was conducted in R using dada2 and phyloseq package. Seventeen (17) phyla were identified, but only seven were remarkably abundant, namely: Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, Verrucomicrobia, Planctomycetes, and Fusobacteria. Double Principal Coordinates Analysis (DPCoA), Principal Coordinate Analysis (PCoA) of Weighted Unifrac Distance and Canonical Correspondence Analysis (CCoA) revealed an association of Proteobacteria to low ammonia concentration in BFT treatment. On the other hand, phylum Bacteroidetes was clustered towards the control, characterized by high ammonia. Overall, BFT has increased Shannon and Simpson diversity indices compared to the control. Regime change in the microbial community was not easily caused by organic C supplementation because of community robustness to withstand biotic and abiotic disturbances. Controlled laboratory experiment showed that some bacteria species proliferate as a response to C:N manipulation, but established species remained dominant.

Concerns relating to cost and availability have directed traditional farmers to expand options on the induced spawning of fish for viable production of seeds. The study was conducted to examine the potential of using pituitary extracts (PE) from goat (Capra aegagrushircus) and pig (Sus scrofa domesticus) on the induced spawning of African catfish (Clarias gariepinus). Pituitary extract of African catfish using 4 mgkg–1 body weight dosage (control) and PE from goat and pig using 4 mgkg–1 and 200 mgkg–1 body weight dosages were single intramuscularly injected to female breeders. Utilisation of goat and pig PE has successfully induced the spawning of African catfish. All female breeders attained ovulation within 10-12 h which is under the prescribed latency period. Total number of eggs spawned ranged from 36200-67600. The three PE used attained comparable result in terms of relative fecundity. Fertilisation rate revealed that PE from goat at 4 mgkg–1 dosage attained similar result to that of control treatment. Hatching period occurred within 24–36 h and goat PE using both dosages gave the highest results in hatching rate. The current study provides preliminary information on the success of using PE from goat and pig for the induced spawning of African catfish.

The study was conducted to assess the biological aspects of yellowfin tuna (Thunnus albacares) caught using hook and line in Dilasag Bay, Dilasag, Aurora, Philippines from July to September 2019. A total of 283 yellowfin tuna (total weight of 12,231.53 kg) was caught in Dilasag Bay by the 10 municipal fishermen in their 283 fishing trips. Large size yellowfin tuna (>110 cm) were commonly caught in Dilasag Bay. The monthly and combined growth data of the fish was described as negative allometric (b <3); the organism grows slender, so it gains length faster than weight. The length-weight relationship equation for the combined catches was W = 2.240 L 1.129 . The over-all value of condition factor (K), growth rate constant (k) and maximum length (L∞) of yellowfin tuna were 1.88±0.12, 0.157 kg/year and 145.117 cm, respectively.