SUMMARYInternal and external feeding on zooplankton may provide scleractinian corals with important nutrients. However, the latter process has never been properly quantified. To quantify the dynamics of zooplankton capture, digestion and release for a scleractinian coral, we performed detailed video analyses of Galaxea fascicularis feeding on Artemia nauplii. A highly dynamic process of prey capture, digestion and release was observed. A single G. fascicularis polyp (N3) captured 558±67 and released 383±75 Artemia nauplii over a 6h interval. On average, 98.6% of prey captured was not ingested. Instead, prey items were clustered into aggregates that were digested externally by mesenterial filaments. In addition, we employed carbon, nitrogen and phosphorus analysis of zooplankton before and after digestion by G. fascicularis colonies (N6). For total organic carbon, 43.1% (0.298±0.148gArtemia ), respectively. For extracoelenteric zooplankton feeding alone, total estimated nutrient inputs for G. fascicularis colonies were 76.5±0.0g organic carbon, 15.2±0.0g organic nitrogen, 2.3±0.2g organic phosphorus and 0.5±0.8g inorganic phosphorus per cm 2 coral tissue per day. These values exceed calculations based on intracoelenteric feeding by up to two orders of magnitude. Our results demonstrate that extracoelenteric zooplankton feeding is a key mechanism of nutrient acquisition for a scleractinian coral. These results are of importance to coral aquaculture and our understanding of benthic-pelagic coupling on coral reefs. Supplementary material available online at

Chaetoceros muelleri is a microalgae class of Bacillariophyta (diatom) which is generally only used as feeds for fishes and shellfish larvae. Nevertheless, the biochemical content of this species is quite high and has the potential to be developed. This research aims to explain the effect of different salinity on the growth and lipid content of Chaetoceros muelleri cultured in a continuous photobioreactor. This research was carried out in August 2018 - February 2019. The research was conducted at the Laboratory of Marine Microbiology and the Laboratory of Bioprocess and Bioprospection of Natural Materials, Faculty of Fisheries and Marine Sciences, Padjadjaran University. The samples of Chaetoceros muelleri isolates were obtained from the Jepara Brackish Water Aquaculture Center. The methods used for the study was a ‘Completely Randomized Design’ (CRD) with four treatments. The salinity used is 15, 25, 35 and 45 ppt. The main parameters observed were growth and lipid content, while the supporting parameters were temperature, and pH. The results of this study showed that the highest lipid content was a salinity treatment of 35 ppt with a value of 25.37% of total dry weight obtained at the end of the culture. Based on growth, the highest density occurred in 25 ppt salinity with a maximum density of 3.80 ± 0.49 x 106 cells. ml-1 and maximum growth rate of 0.36 ± 0.008 div. day-1

In order to determine optimal feeding regimes for captive corals, prey capture by the scleractinian coral Galaxea fascicularis was determined by measuring clearance of prey items from the surrounding water. Colonies of G. fascicularis (sized between 200 and 400 polyps) were incubated in 1300 ml incubation chambers. Nauplii of the brine shrimp Artemia sp. were used as the prey item. A series of incubation experiments was conducted to determine the maximal capture per feeding event and per day. To determine maximal capture per feeding event, total uptake of nauplii after one hour was determined for different prey item availabilities ranging from 50 to 4000 nauplii per polyp. To determine maximal capture per day, the corals were subjected to four repetitive feeding events at three different prey item densities (50, 100 and 150 nauplii per polyp). Alongside these quantitative experiments, it was tested to what extent the feeding response of corals is triggered by chemical cues. One hour after food addition, extract of Artemia nauplii was added to the incubation chambers to test its effect on subsequent prey capture rates. In all experiments, prey capture was expressed as the number of nauplii consumed per coral polyp. Total capture of Artemia nauplii by G. fascicularis after a single feeding event increased linearly up till a prey item availability of 2000 nauplii per polyp. Maximal capture per feeding event was estimated at 1200 nauplii per polyp, which is higher than rates reported in previous studies. It became apparent that at high densities of Artemia nauplii, the clearance rate method does not discriminate between active capture and passive sedimentation. Repetitive feeding with 50 nauplii per polyp resulted in a constant total prey capture per feeding event. At a supply of 100 nauplii per polyp, total capture decreased after the first feeding event, and remained constant during the subsequent feeding events at a level comparable to the lower food availability. However, at a supply of 150 nauplii per polyp, total capture per event was higher throughout the entire four-hour incubation period, which obfuscates an accurate estimation of the maximal daily food uptake. In all incubations, a decrease in capture efficiency was observed within the course of the feeding event. In all repetitive feeding experiments, capture efficiency increased immediately upon addition of a new batch of food. This increase in efficiency was not caused by a priming effect of extract of Artemia. The inconsistencies in the data show that estimates of prey capture based on clearance rates should be interpreted with caution, because this method does not take into account potential dynamics of prey capture and release.

This research aims to determine the nutritional content and the best treatment for the addition of Lemna sp. fermented for the growth of sangkuriang catfish. The research was conducted from February to August 2022, in Aquaculture Laboratory of the Fisheries and Marine Science Faculty, Universitas Padjadjaran. The method used in this research is experimental, and is of a Completely Randomized Design (CRD). It consists of four treatments and four repetitions, namely treatment A (control) treatment B (10% fermented lemna + 90% commercial feed), Treatment C (20% fermented lemna + 80% commercial feed), and Treatment D (30% fermented lemna + 70% commercial feed). Parameters observed were changes in nutrient content of lemna, daily growth rate, feed conversion ratio, survival rate, and water quality. Data were analyzed using ANOVA analysis of variance and if there was a significant difference, Duncan test was performed with a 95% confidence level, while changes in nutrients in lemna and water quality were analyzed descriptively. The results of the proximate analysis showed that the fermented lemna using BIOM-S probiotics experienced changes in the nutritional content, namely an increase in protein content from 25.24% to 33.66% and a decrease in crude fiber from 11.93 to 9.13%. Based on the results of this research, the treatment C (20% fermented lemna + 80% commercial feed) the best results in a daily growth rate at 1.92%/day, a feed conversion ratio at 1.41, and a survival rate of up to 97.5%.