Publications
References and Links to Papers
2020
Anguilla bicolor (McClelland, 1844) is one of the native Indonesian fish. Anguillids species exhibit catadromous life mode, that they are born in marine waters, then migrate as larvae to fresh or brackish water where they grow and mature before they return to the marine environment. The fresh water to marine migration was designed to reach their spawning side. Anguilla bicolor is a fish that exhibit extreme migration and can travel up to 2000 km. During migration Eel abstain from food and loose substantial amount of bone, where bones were reused as energy during migration. The cellular bone serves as a source of mineral release following osteoclastic resorption. The eel's skeleton is structurally optimized to meet the metabolic challenge of fasting and simultaneous sexual development during migration. This study aimed to investigate the structure and ossification of vertebrae of Anguilla bicolor on glass eel and early elver eel phase. The study was following standard Inouye bone staining method. Result showed the number of vertebrae segments in the glass eel and early elver eel stage were 104 segments, all vertebrae segment already well calcified. However, both eel stage exhibit differences on bone length ratio, and the cranial bone ossification processes. The glass eel cranial bone mainly consists of cartilage bone, while in the early elver eel phase the cranial bone already ossified become compact bone.
2020
Research on the behavior of eels with bioacoustics has never been done, because eels are catadromus fish that lay eggs in the deep sea and then grow in freshwater area. This study aims to observe the behaviour of Anguilla bicolor when feeding with passive sonar bioacoustic methods by hydrophone in the elver and yellow phases. The eel is placed in an aquarium and fed with pellets. The data were processed to get the duration and characteristics (frequency and intensity) of sound. Data were analyzed using the Duncan Multiple Range Test (DMRT) to determine the difference in the sound of eel before and during feeding. The results showed that the duration of the sound of the elver phase fish was significantly different for the duration before and after feeding, but for the yellow phase, the duration before and after feeding was not significantly different. When compared between the elver and yellow phases for before and when feeding both are significantly different. The sound pattern of elver phase itself is significantly different for before and after feeding, as well as for the yellow phase. When compared between the elver phase and the yellow phase on the sound pattern before feeding it was not significantly different, so did the sound pattern of the elver phase when feeding was not significantly different than the yellow phase sound when feeding. The conclusion of this study shows that the bioacoustic of eel fish comes from the movement of fish when swimming. Each phase of eel has different sound characteristics seen before feeding or when feeding.
2020
Indonesian shortfin eel, Anguilla bicolor (McClelland, 1844) is one of fish that have swim bladder to assist swim and doing migration. Every fish has different shape, gas volume, dimension, and length ratio of swim bladder, which can play role in the difference in backscattering of acoustic energy. This study aims to determine the shape, dimensions and ratio of Anguilla bicolor's swim bladder and their effect on target strength (TS) values. The research was conducted in two places, in the Acoustic lab, Department of Marine Science and Technology, Bogor University and Laboratory of Histology and Embryology, Faculty of Biology, Universitas Gadjah Mada. Retrieving data using the EK-15, Frequency 200 KHz tool and also the X-ray photo. The results show the shape of the swim bladder of Anguilla bicolor is elongated and consists of 1 room which is generally called a closed swim bladder. Acoustic detection results show that fish with large swim bladder volumes have large TS values and conversely fish with small swim bladder volumes have a small TS value.
2020
Sufficient availability of good food quality is important for fish aquaculture in order to increase fish production. Microalga is one of alternative protein sources, and one among those is Chorella sp. Protein content of Chlorella sp. is very high, around 51- 58 % and consists of various kinds of essential fatty acids, which is important for fish nutrition. Recently, Algae also prospective source of ethanol biofuel. Ethanol extraction usually produce waste material, which still consist of high protein content, which valuable for fish feed sources. Therefore, the study aimed to examine the effects of fish food derived from algae biofuel-waste on growth and histological structure of wader pari (Rasbora lateristriata) intestine. Fish were divided into 5 groups of control negative (no additional protein), feed with waste algae, waste + Fresh algae, fresh algae and commercial fish food, respectively. The fish morphometry, weight, and intestine histological structure were examine. The results showed that fish feed treatment gave effect on fish growth and instestine histological structure. Algae waste feed showed similar performance to commercial fish feed on fish growth and showed no negatif effect on intestine villi length and goblet cells number, evidenced good prospect of algae waste as fish feed.
2018
The movement of eels produces a sound called a hydrodynamic sound which is the sound or vibration that results from a change in the medium due to the movement of fish. Hydrodynamic sound intensity occurs when the direction and speed of fish swimming change rapidly. The deflection of the head position will cause a strong displacement of the medium. The displacement causes changes in pressure waves on the medium, which can be detected as sound by the hydrophone. This research aims to analyze the differences in the sound of elver phase eel fish and yellow phase in controlled conditions. The research was conducted at the Laboratory of histology and embryology of the Faculty of Biology, Gadjah Mada University. The research time is August 4-7, 2016. The tools used in this research are: Aquarium glass, headphones, hydrophone, Seaphone, alkaline battery box, laptop. The ingredients used were 5 yellow phase eel and elver phase respectively. Data processing is carried out with the help of the wavelab program 6 and analyzed using the Duncan Multiple Range test (DMRT). The results showed that the elver and yellow phase ell activities are very diverse in terms of the duration of eel's sound during morning, afternoon and night. Sound frequencies patterns recorded from 0 - 22.03 KHz. The sound frequency of ell is dominant from 151 - 450 Hz of range, and has different sound patern during morning, afternoon and night. The conclusion is that the duration and hydrodynamic sound patterns of elver phase eel and yellow phase were significantly different between morning - afternoon, also afternoon – evening, but for the morning - the evening is not significantly different.