Male Blue Gourami (Trichogaster trichopterus) Nest-Building Behavior Is Affected by Other Males and Females

In this study, we examine male blue gourami (Trichogaster trichopterus) nest-building behavior that is affected by other males and interactions under experimental conditions. Males found in the area control the territory and sexual behavior, and are influenced by the behavior of other males. The results of this study show that the sexual behavior (nest-building) of male blue gourami is affected both by the behavior and pheromones of other males. We suggest that males must defend their territories in order to prevent these two factors from interfering in nest-building.

Involvement of GnRH and Gonadotropin Genes in Oocyte Development of Blue Gourami Females (<i>Trichogaster trichopterus</i>)

The goal of this study was to gain a fundamental understanding of RnRH 1 and 3, as well as FSH and LH action, in ovarian follicles during oocyte growth by examining changes in ovarian gene transcription in blue gourami females (Trichogaster trichopterus). The levels of target ovarian mRNAs were determined by quantitative real-time PCR. GnRH1 mRNA levels were higher in oocytes at the previtellogenic stage compared to the vitellogenic and follicular oocytes maturation (FOM) stages. No significant differences in GnRH3 mRNA levels were detected among oocytes during the different stages of development. βLH and βFSH mRNA levels were lower in oocytes at the vitellogenic stage compared to the previtellogenic stage. The high transcription of GnRH 1 and 3 in the brain and of FSH and LH in the pituitary of blue gourami as was found in previous studies in our laboratory, compared to mRNA levels changed in ovary during oogenesis, supporting the hypothesis that differences exist between the function of endocrine and autocrine/paracrine of these hormones.

Expression of SOX3 and SOX9 Genes in Gonads of Blue Gourami

In vertebrates, SOX (SRY-related HMG box) genes are thought to be due to major gene duplication events, initially occurring during early stages of metazoan evolution and later during the transition between non-vertebrate chordates and vertebrates. The aim of this study is to examine SOX3 and SOX9 transcription in oogensis and spermatogenesis in a fish model, the blue gourami (Trichogaster trichopterus). In females during oogenesis, SOX9 mRNA levels were lower compared to SOX3 mRNA levels. In males, SOX9 mRNA levels were higher in testes compared to SOX3 mRNA levels, however no significant differences between SOX3 and SOX9 mRNA levels were observed in the gonads of males that were kept under non-reproductive conditions compared to males kept with females under reproductive conditions and that were nest-builders.

Somatolactin Transcription during Oogenesis in Female Blue Gourami (<i>Trichogaster trichopterus</i>)

Somatolactin (SL), a specific pituitary hormone belonging to the prolactin (PRL) super family, is involved in background adaptation, osmoregulation, reproduction and fatty acid metabolism. The goal of this study was to examine the gene transcription of SL changes in the ovary of blue gourami females (Trichogaster trichopterus) during oogenesis by quantitative real-time polymerase chain reaction (Real-Time PCR). Somatolactin in the pituitary was higher in females at low vitellogenesis compared to females with oocytes in maturation, and the difference was significant (p < 0.05). No significant differences were found in mRNA levels between low and high vitellogenesis, and high vitellogenesis and maturation. The findings of this and previous studies demonstrate that SL, growth hormone (GH) and PRL are involved in oogenesis in blue gourami;however, considerably more studies are required in order to separate the functions of these hormones.

Substitution of Silkworm Pupae （Bombyx mori） for Fish Meal in Broodstock Diets for Snakeskin Gourami （ Trichogaster pectoralis）

Substitution of silkworm pupae （Bombyx mori） for fish meal in broodstock diets for snakeskin gourami （Trichogaster pectoralis） was conducted in order to evaluate the effect of silkworm pupae on feed digestibility and broodstock performance. Snakeskin gourami broodfish were fed with isocaloric diets （DE 3,000 a： 50 Kcal/kg） contained 32% crude protein. The levels of substitution were 0%, 50%, 75% and 100% of protein from fish meal （equal to 0%, 14.57%, 21.75% and 29.03% silk worm by weight）. The study was assigned in CRD with 4 treatments and 3 replications. Six hundred of snakeskin gourami with five-month old and average weight of 78.67 ± 2.15 g in female and average weight of 73.00 ± 2.49 g in male were stocked in 12 cages. Fifty fishes of 25 females and 25 males were reared in each cage and fed experimental diet for five months. The result indicated that protein digestibility of test diets were significantly decrease （P 〈 0.05） according to the level of silkworm pupae in diets where as the dry matter digestibility showed no significantly different （P 〉 0.05）. The growth performance and egg fecundity were significantly decreased （P 〈 0.05） according to the levels of silkworm pupae. In contrast, egg quality in term of fry number on first spawned, fingering number on first spawned were not significantly different （P 〉 0.05）. The survival rate of one month nursing fish on first spawned were significantly different （P 〈 0.05）. Hence, silkworm pupae could substitution for 50% of protein from fish meal （14.57% by weight） in snakeskin gourami broodstock diets without any adverse effect on egg quality.

条纹短攀鲈的交配习性和筑巢生境(英文)

条纹短攀鲈栖息于静止、植被茂密、靠近稻田和池塘边缘的浅水中。本文研究了它在泰国稻田和小池塘两种生境中的繁殖特征。与池塘相比,稻田筑巢地的pH值、溶解氧的含量和温度较高,而电导、溶解的固体物浓度较低,水也较浅。稻田中的种群密度低于池塘。雄性个体的体重和体长均大于雌性个体,且其体重与体长和体宽正相关,但雌性个体的体重仅与体长正相关;泡巢的面积与雄性个体的体长和重量均不相关。繁殖期间,条纹短攀鲈雌、雄个体交尾多次。每次交尾产卵3.74±1.02(Mean±SD)粒,每个繁殖季节交尾84±12.97次;在一个持续178±51.17min的产卵时段里,条纹短攀鲈平均产卵314±109.77粒。鱼苗孵化需30.75±0.55h,2日龄个体的大小平均为3.21±0.29mm。

条纹短攀鲈的雄性个体大小、雌性偏好以及雄性之间的竞争(英文)

本研究考察了条纹短攀鲈(Trichopsis vittata)雄性个体的身体大小对雌性个体性偏好的影响以及对雄性之间竞争的影响。本研究设立了两种处理来研究雌性个体的性偏好以及雄性之间的竞争。在一种处理中,放入同样大小的雄性个体,而在另一种处理中,放入大小不同的雄性个体。结果表明,雄性个体的大小不影响雌性条纹短攀鲈的性偏好。在对雄性之间竞争的研究中,发现个体较大的个体获胜的次数比较多。在个体大小相同的处理中,雄性之间打斗的持续时间比另一种处理中的打斗持续时间长。对这两种处理中不同对抗行为的比较表明,个体大小相同处理组中的发声、咬、以及总体对抗行为发生得更为频繁。对个体大小不同处理组中的大、小个体的进一步观察也揭示出体型大的个体比体型小的个体有更多的追逐行为和更少的逃脱行为。这些结果表明,在雄性个体比雌性个体大的物种中,体型的性两型可能与雄性之间的竞争有关,而不是与雌性偏好有关。

GENETIC CONSEQUENCES OF INTRODUCED Gouramy Helostoma Temminckii (Pisces: Helostomatidae) IN BRUNEI'S WETLAND

Kissing gouramy (Helostoma temminckii) was introduced into Tasek Merimbun in the 1980's. We studied their genetic profile using allozyme electrophoresis and found that all loci were monomorphic. The loss of heterozygotes may suggest that the gouramy are inbreds. They must have reproduced by repeated sib-mating over the years. The severe drought in Tasek Merimbun may have aggravated the genetic erosion further. The genetic variability of kissing gouramy in terms of % polymorphic loci, mean number of alleles per loci and observed heterozygosity level were lower than cyprinids in the same lake and kissing gouramy from the wild. We also note that kissing gouramy is a fast grower and may threaten the livelihood of indigenous fishes in the lake.

Acoustic and visual adaptations to predation risk: a predator affects communication in vocal female fish

Predation is an important ecological constraint that influences communication in animals.Fish respond to predators by adjusting their visual signaling behavior,but the responses in calling behavior in the presence of a visually detected predator are largely unknown.We hypothesize that fish will reduce visual and acoustic signaling including sound levels and avoid escalating fights in the presence of a predator.To test this we investigated dyadic contests in female croaking gouramis(Trichopsis vittata,Osphronemidae)in the presence and absence of a predator(Astronotus ocella-tus,Cichlidae)in an adjoining tank.Agonistic behavior in T.vittata consists of lateral(visual)displays,antiparallel circling,and production of croaking sounds and may escalate to frontal displays.We analyzed the number and duration of lateral display bouts,the number,duration,sound pressure level,and dominant frequency of croaking sounds as well as contest outcomes.The number and duration of lateral displays decreased significantly in predator when compared with nopredator trials.Total number of sounds per contest dropped in parallel but no significant changes were observed in sound characteristics.In the presence of a predator,dyadic contests were decided or terminated during lateral displays and never escalated to frontal displays.The gouramis showed approaching behavior toward the predator between lateral displays.This is the first study supporting the hypothesis that predators reduce visual and acoustic signaling in a vocal fish.Sound properties,in contrast,did not change.Decreased signaling and the lack of escalating contests reduce the fish's conspicuousness and thus predation threat.