Reproductive Cycle of Spondylus varius (Sowerby, 1827) in Lianga Bay, Surigao Del Sur, Eastern Mindanao, Philippines

The reproductive cycle of the Spondylus varius in Lianga Bay, Surigao del Sur, Philippines, was studied from September 2018 to October 2019. Histological examination showed that this species is gonochoric. The spawning occurred at the size of 80-100 mm shell length. Spondylus varius showed a continuous breeding season from December to April. The highest peak was recorded in April 2019. From August to October, the early and late gametogenesis stage predominates. Annual gonad development and spawning period coincided with the increase in sea surface temperature. In terms of management, it is important to leave a proportion of reproductively mature individuals in the population to allow breeding and recruitment. Thus, it is recommended that the collection of individuals smaller than 65 mm should be restricted and a ban on fishing imposed from February to May

LETHALITY AND ANTIMICROBIAL SCREENING OF SEA HARE (Dolabella auricularia) INK AGAINST THE FISH PATHOGENS

This study determined the potential of sea hare’s (Dolabella auricularia) ink as a microbial agent in fish pathogens. The output of this study provides additional information to replace the expensive and hazardous antibiotics that are already being applied in aquaculture. Six (6) fish pathogens were tested for antimicrobial assays. The results revealed that all of the six (6) pathogens undergo growth inhibition in different concentrations. The Escherichia coli, Enterococcus faecalis, Vibrio cholera, and Staphylococcus epidermidis showed maximum activity (very active) against the Salmonella sp. and Proteus vulgaris with "partially active" observation. For the toxicity analysis for nauplii, the LC50 value is 529.12, indicating that the sea hare’s ink is moderately toxic. This is to recommend testing its bioactive secondary metabolites with the possibility of use in the enhancement of new pharmaceutical agents against aquaculture disease. A better understanding of its ink could lead us to the development of new therapeutics