Food and Feeding Habits of Bilih Fish Mystacoleucus padangensis (Bleeker, 1852) In Naborsahan River, Toba Lake, North Sumatera

Abstract

The bilih fish Mystacoleucus padangensis did a migration of the lake to the river that empties into the lake to spawn. This study aimed to determine whether migratory fish bilih ate when and what kind of natural foods consumed by bilih fish in it migration habitat. The study was conducted in Naborsahan River, Toba lake, North Sumatra. Sampling was done every 1 hour using Cast net. The results showed that bilih fish keep doing the feeding activity and having diurnal when migrated. The natural food bilih fish in the river and Toba lake was same, it was the phytoplankton of the class Bacilariopiceae. Natural food bilih fish that found in it intestine were phytoplankton include Rhizosolenia, Synedra, Gonatozygon, Closterium, Surirella, Pinnularia, Oscillatroria, Melosira, Gyrosigma, Aulacoseira and Zooplankton among others Creseis, Tubifex and Daphnia. The type of natural food that nostly found in bilih fish intestines were phytoplankton from the genus Synedra Bacilariopiceae with Index of Preporedance (IP) is 97.9 %. Based on the composition of the natural food that was dominated, bilih fish was categorized as the plankton feeder.

Broodstock development, induced spawning and larval rearing of the bilih, Mystacoleucus padangensis (Bleeker, 1852), a vulnerable species, and its potential as a new aquaculture candidate

“…In the wild, it varies from 3,469 to 6,531 eggs/fish. 21 The female weight of broodstock and absolute fecundity had a strong relationship (r 2 = 95%, P = 0.000). The differences in absolute fecundity in maturing broodfish depend on the brood weight, age of broodfish, and species, including strain.…”

“…The gonadal maturity stages (GMS) II, III, and IV of the female broodstock were classified as follows 21 : in GMS II, the ovary containing the egg is dark green and visible to the naked eye; in GMS III, the ovaries fill approximately 70% of the abdominal cavity; eggs are greyish-green, visible to the naked eye, and larger than they are in GMS II; and in GMS IV, the ovaries fill approximately 80% of the abdominal cavity; visually, the ovaries contain greyish-green eggs that are larger and vary in size and the blood vessels are visible, especially in the ventrolateral area. Before hormone injection for ovulation, oocyte samples were taken from females in vivo as described previously 21 and were placed in Serra's solution (6:1:1; 70% ethanol, 40% formaldehyde, and 99.5% acetic acid) for five minutes to determine the position of the cytoplasm. Then, the oocyte nucleus was classified using a four-stage scale as follows.…”

“…19,20 M. padangensis, a small Cyprinid, grows to approximately 20 cm and weighs 12 grams. 21 This species has a high potential market demand but is threatened by overfishing and has not been successfully cultured. 22 M. padangensis has been categorised as "vulnerable" by the International Union for Conservation of Nature (IUCN).…”

Broodstock development, induced spawning and larval rearing of the bilih, Mystacoleucus padangensis (Bleeker, 1852), a vulnerable species, and its potential as a new aquaculture candidate

“…The broodstock is anesthetized orally with clove oil in 0.5 mL/10 L of water for ten minutes. The gonadal maturity stages (GMS) II, III, and IV of the female broodstock were classified as follows 21 : in GMS II, the ovary containing the egg is dark green and visible to the naked eye; in GMS III, the ovaries fill approximately 70% of the abdominal cavity; eggs are greyish-green, visible to the naked eye, and larger than they are in GMS II; and in GMS IV, the ovaries fill approximately 80% of the abdominal cavity; visually, the ovaries contain greyish-green eggs that are larger and vary in size and the blood vessels are visible, especially in the ventrolateral area. Before hormone injection for ovulation, oocyte samples were taken from females in vivo as described previously 21 and were placed in Serra's solution (6:1:1; 70% ethanol, 40% formaldehyde, and 99.5% acetic acid) for five minutes to determine the position of the cytoplasm.…”