The objective of this experiment was to evaluate soy-protein-concentrate (SPC, 65% protein) as a replacement ingredient for ®shmeal (FM, 65% protein) in shrimp diets. Shrimps (Penaeus monodon, PL-15) were raised in the laboratory to 1.5 g body weight and were then transferred into 120-L aquaria with water temperature maintained at 28 T 2°C. Five isonitrogenous and isocaloric diets (protein 36%, ME 15.7 kJ g ±1 ) were prepared using SPC at inclusion levels of 0, 8.75, 17.50, 26.25 and 35% by replacing 0, 25, 50, 75 and 100% of the FM from the diet, respectively. All diets contained 12% soybean meal. The diets were randomly assigned to 45 aquaria (n = 9), each containing 30 shrimps. Shrimps were fed to satiation four times a day for an 8-week period and were exposed to alternating 12 h light and dark periods. Aggregate body weight for each aquarium was recorded every 2 weeks, when shrimps were also counted.The feed intake by shrimps was not different at 0, 25 or 50% FM substitution levels, but was signi®cantly decreased at 75 and 100% substitution levels. The body weight gains of shrimp fed diets with 0, 25 or 50% FM substitution were signi®cantly better than those fed diets with 75 or 100% FM substitution. A 100% substitution of FM from the diet had a severe negative effect on the body weight gain. With increasing substitution of FM with SPC, the feed ef®ciency ratio, protein ef®ciency ratio, and protein and fat gain in the shrimp followed the same general pattern as described for body weight. Mortality was not signi®cantly different among the dietary treatments. These data indicate that a 17.5% inclusion of SPC in the diet of P. monodon can support normal growth of the shrimp with the potential for substituting FM.

The catfish family Siluridae contains 107 described species distributed in Asia, but with some distributed in Europe. In this study, karyotypes and other chromosomal characteristics of 15 species from eight genera were examined using conventional and molecular cytogenetic protocols. Our results showed the diploid number (2n) to be highly divergent among species, ranging from 2n = 40 to 92, with the modal frequency comprising 56 to 64 chromosomes. Accordingly, the ratio of uni- and bi-armed chromosomes is also highly variable, thus suggesting extensive chromosomal rearrangements. Only one chromosome pair bearing major rDNA sites occurs in most species, except for Wallago micropogon, Ompok siluroides, and Kryptoterus giminus with two; and Silurichthys phaiosoma with five such pairs. In contrast, chromosomes bearing 5S rDNA sites range from one to as high as nine pairs among the species. Comparative genomic hybridization (CGH) experiments evidenced large genomic divergence, even between congeneric species. As a whole, we conclude that karyotype features and chromosomal diversity of the silurid catfishes are unusually extensive, but parallel some other catfish lineages and primary freshwater fish groups, thus making silurids an important model for investigating the evolutionary dynamics of fish chromosomes.

The first chromosomal characteristics of nucleolar organizer regions (NORs) and karyological analysis of triangle butterflyfish (Chaetodon triangulum) and yellow butterflyfish (C. andamanensis) from Andaman Sea, Phuket and Phang Nga Province, Thailand, were studied. Kidney cell samples were taken from five male and five female fish. Mitotic chromosome preparations were conducted using standard squash technique as well as taken directly from kidney cells. Metaphase spreads were performed on microscopic slides and then airdried. Conventional and Ag-NOR banding techniques were applied to stain the chromosome. The results showed that the diploid chromosome number of C. triangulum and C. andamanensis was 2n=48, and the fundamental numbers (NFs) were 48 and 52, respectively. Karyotpes were present as 46 large telocentric and two medium telocentric chromosomes in C. triangulum; and 2 large metacentric, 8 large telocentric, 34 medium telocentric, 2 medium acrocentric, and 2 small telocentric chromosomes in C. andamanensis. No strange sized chromosomes related to sex were observed. After the Ag-NOR banding technique, one pair of NORs was observed on the long arm centromeric region of large telocentric chromosome pair 21 in C. triangulum and on the long arm subcentromeric region of the largest metacentric chromosome pair 1 in C. andamanensis. The karyotype formulas are as follows:

The present study aims to analyze concerned karyotyping and idiograming of the three-spot damselfish (Dascyllus trimaculatus

Karyotype and nucleolar organizer regions (NORs) were studied in the longfin carp (Labiobarbus leptocheilus) from Mekong Basin of Thailand. The mitotic chromosomes were directly prepared from kidney cells from five male and five female fishes and stained by conventional staining and Ag-NOR banding. The chromosome number was 2n=50 and the fundamental number (number of the chromosome arms, NF) was 86 in both male and female fishes. The karyotype was composed of six large metacentric, eight large acrocentric, six large telocentric, four medium metacentric, six medium submetacentric, six medium acrocentric, four medium telocentric, four small metacentric, two small acrocentric and four small telocentric chromosomes. The Ag-NOR banding showed a single pair of Ag-NORs adjacent to the telomeric position of the short arm of the chromosome pair 8.

This is the first nucleolar organizer region (NOR) polymorphism and chromosome analysis of Banggai cardinalfish (Pterapogon kauderni Koumans, 1933). Kidney cell samples were taken from 10 male and 10 female fish. Mitotic chromosome preparations were prepared directly from kidney cells. Conventional and Ag-NOR banding techniques were applied to stain the chromosomes. The results showed that the diploid chromosome number of P. kauderni was 2n=46, and the fundamental number (NF) was 92 in both males and females. The types of chromosomes were 6 large acrocentric, 4 medium metacentric, 14 medium submetacentric, and 22 medium acrocentric chromosomes. The results indicated that the short arm subtelomeric of the acrocentric chromosome pair 13 showed clearly observable NORs. This finding exhibited that three NOR polymorphism patterns were found: 1) homomorphic which shows an equal size of both chromosome pair 13 (13a13a), 2) heteromorphic that displays different sizes of NORs of chromosome pair 13 (13a13c) and 3) heteromorphic which is found in only one homologous chromosome pair 13 (13a13b). There was no observation of strange size chromosomes related to sex. The karyotype formula for P. kauderni was: a m sm a 6 4 14 22 2 (diploid) 46 = L + M + M + M n

Twelve, 400‐m2 earthen ponds at Walailak University, Thailand, were used to investigate the effects of fertilizer application rates on water quality, bottom soil, and production of giant gourami, Osphronemus goramy. Fertilizer rates of 0, 6, 9, and 12 kg N plus 0, 3, 4.5, and 6 kg P2O5 /ha (N:P2O5 = 2:1) applied at 3‐wk intervals were replicated three times in a completely randomized design. Ammonium phosphate and ammonium sulfate were sources of nitrogen and phosphorus. Fish averaged 8.8 g and were stocked at 1 fish/m2. The highest final weight, growth rate, and net production of giant gourami were achieved with 9 kg N plus 4.5 kg P2O5/ha. Chlorophyll a concentration was correlated with total nitrogen concentration (R2 = 0.574; P < 0.05) and total phosphorus concentration (R2 = 0.600, P < 0.05). Fish production and chlorophyll a concentration were also correlated (0.826; P < 0.05). Chlorophyll a concentration and fish production declined at total hardness concentrations above about 50 mg/L – likely from precipitation of fertilizer phosphorus as calcium phosphate. Pond bottom soil properties did not change in relationship to fertilizer rate.

This study examines for the first time of karyotypic analysis and chromosomal characteristic of nucleolar organizer regions/NORs of Epinephelus sexfasciatus. The fish samples were collected from Andaman Sea, Phuket province, southern Thailand. The chromosomes were investigated using conventional Giemsa’s staining and Ag-NORs banding techniques. Fish chromosome preparations were conducted by squash technique from kidney. The results showed that the diploid chromosome number of E. sexfasciatus was 2n=48 and the fundamental number (NF, number of chromosome arms) was 48. The type of chromosomes included 24 large telocentric and 24 medium telocentric chromosomes. After Ag-NOR banding technique, single pair of NORs was observed on the short arm of medium telocentric chromosome pair 23. The idiogram shows gradually decreasing length of the chromosomes. A size difference of the largest and the smallest chromosomes is approximately two folds. The karyotype formula could be infered as: 2n(48) = 2n(48)= Lt24+Mt24.