Search

Synthetic hormones are widely used for induced breeding with significant successes. This study compared spawning successes in paradise fish (Macropodus opercularis) using synthetic hormone (Ovaprim) and natural simulation in glass tanks (0.3m x 0.6m). The experiment was conducted in two parts using two males and two females brood fish. The weights of the fish were between 4.0 and 5.0g for the males and 5.0 and 6.0g for the females. For the induced spawning, Ovaprim was injected intramuscularly according to the fish body weight after which they were left to spawn. The group on natural spawning were not induced by any hormone. Hatching of the eggs occurred within 48 hours at a temperature of 28.80C. Total number of eggs obtained by artificial and natural breeding were 430 and 322eggs respectively. Percentage fertilization in artificial breeding was 63.26% while 41.93% was recorded in natural breeding. Fry were raised on compounded diet for 6 weeks. Results showed that artificially bred fish had a higher mean weight gain (2.31 g) and survival rate (48.17%) than those from natural breeding having 2.10 g and 44.26% respectively. The results suggest that artificial breeding using synthetic hormone (Ovaprim) yielded better spawning success and survival rate than natural process. Keywords: Paradise fish, natural breeding, hormone, fertilization, survival

Macropodus opercularis (Linnaeus) (Fig. 111, EAs[SPC]) References. Tan et al., 2013. Distribution. Bukit Brown (Tan et al., 2013). Remarks. This species is sometimes sold as live feed in the ornamental fish trade (Tan HH, pers. obs.)., Published as part of Hui, Tan Heok, Peng, Kelvin Lim Kok, Huan, Liew Jia, Wei, Low Bi, Hing, Rayson Lim Bock, Beng, Jeffrey Kwik Teik & Yeo, Darren C. J., 2020, The non-native freshwater fishes of Singapore: an annotated compilation, pp. 150-195 in Raffles Bulletin of Zoology 68 on page 183, DOI: 10.26107/RBZ-2020-0016, http://zenodo.org/record/5343987, {"references":["Tan JYH, Tan LHC, Quek G, Lim VSF & Tan HH (2013) The fish fauna of Bukit Brown, Singapore. Nature in Singapore, 6: 229 - 237."]}

The round-tailed paradise fish (Macropodus ocellatus) is important to the local ecosystem and economy. Other species in the genus Macropodus are undergoing population declines, indicating that the M. ocellatus population might also be declining. Therefore, the status of M. ocellatus, related to standing-water ecosystem stability and sustainable utilization of fishery resources, requires attention. In this study, we assessed the spatial pattern of the M. ocellatus genetic structure in 10 localities from China. Sequencing of Cytb (1135 bp) and the D-loop (668 bp) yielded 26 and 10 haplotypes, respectively. A total of 30 haplotypes were identified among 165 concatenated mitochondrial DNA sequences. The results showed that the total haplotype diversity of the 10 populations is high (0.910) and that genetic diversity indices for sequences from HuaiAn were the highest (haplotype diversity Hd = 0.780, nucleotide diversity pi = 0.00363). The results of AMOVA indicated that most genetic variation was among populations within groups (80.22%, P

Adults of Paradise fish Macropodus opercularis are easily maintained in the laboratory. The fertilized eggs of Paradise fish were natural inseminated and incubated in room temperature (range 22.5 to 25.7°C). We carefully observed the process of embryonic development and divided them into 28 stages based on diagnostic features of the developing embryos. The principal diagnostic features are the number and size of blastomeres, form of the blastoderm, extent of epiboly, development of the central nervous system, number and form of somites, optic and otic development, heart development, blood circulation, the size and movement of the body, and development of the tail.

It has hitherto been unknown whether the paradise fish Macropodus opercularis that inhabits the Ryukyu Archipelago, Japan, is native to the region or was introduced. This study examined the genetic identity of fish from five islands in the Ryukyu Archipelago (Okinoerabu, Okinawa, Yagaji, Kume, and Minamidaito islands) and compared it with those from Taiwan Island, mainland China, and Hainan Island. Analyses of the mtDNA control (760 bp) and cytb (660 bp) regions showed that haplotypes of specimens from the Ryukyu Archipelago were the same as or were very similar (with a 1- or 2-bp difference) to those from Taiwan. In addition, haplotypes from the Ryukyu Archipelago also showed lower genetic diversity than those from Taiwan Island, mainland China, and Hainan Island. These results suggest a high likelihood that the fish in the Ryukyu Archipelago were artificially introduced from Taiwan. However, the possibility that the fish is indigenous to the Ryukyu Archipelago cannot be completely ruled out, because some haplotypes and a clade from the Ryukyu Archipelago have not been found in the other areas. Regardless of its origin, we emphasize the importance of the conservation of the paradise fish in the Ryukyu Archipelago as an indicator of the threatened wetland environment as well as for its cultural value.

Thanks to its small size, external fertilization and fecundity, over the past four decades, zebrafish (Danio rerio) has become the dominant fish model species in biological and biomedical research. Multiple lines of evidence, however, suggest that the reliance on only a handful of genetic model organisms is problematic, as their unique evolutionary histories makes them less than ideal to study biological questions unrelated to their historically contingent adaptations. Therefore, a need has emerged to develop novel model species, better suited for studying particular problems. The paradise fish (Macropodus opercularis) has a much more complex behavioral repertoire than zebrafish and has been a favored model animal in ethological research during the last decades of the previous century. We believe that with currently available, easily adaptable genetic toolkits, this species could be easily developed into a popular model of behavioral genetics. Despite its earlier popularity, however, the description of a detailed housing and husbandry protocol for this species is still missing from scientific literature. We present here a detailed description of how to raise and breed paradise fish successfully under laboratory conditions, and also discuss some of the challenges we faced while creating a stable breeding population for this species in our facility.

The aggressive behavior of male paradise fish (Macropodus opercularis) was studied. Fish were subjected to three aggressive encounters on consecutive days. If submissive males encountered the same opponent three times, the last aggressive encounter was very different than the first one. When the animals faced a new opponent each day, the changes were much less pronounced. We conclude that (1) fish are able to recognize their opponents at least one day after the encounter ("social recognition"), and (2) social recognition modifies the effect of prior defeat ("status-related memory") in subsequent encounters.

Aquatic air-breathing anabantoids, a group of fish species characterized by the presence of a labyrinth organ and some gills, exhibit morphological variations. This study aimed to examine whether unequal gill growth begins during the early stages and described the sequence of the early gill developmental events in Betta splendens and Macropodus opercularis. To determine when the ion regulatory and gas exchange abilities first appear in the gills, mitochondria-rich cells (MRCs) and neuroepithelial cells (NECs) were examined in young B. splendens. To evaluate the relative importance of the gills and the labyrinth organ under different levels of oxygen uptake stress, the levels of carbonic anhydrase II (CAII) and Na(+)/K(+)-ATPase (NKA) protein expressions in 2 gills and the labyrinth organ were examined in M. opercularis. We found that the first 3 gills developed earlier than the 4th gill in both species, an indication that the morphological variation begins early in life. In B. splendens, the MRCs and NECs clearly appeared in the first 3 gills at 4 dph and were first found in the 4th gill until 11 dph. The oxygen-sensing ability of the gills was concordant with the ionoregulatory function. In M. opercularis, the hypoxic group had a significantly higher air-breathing frequency. CAII protein expression was higher in the labyrinth organ in the hypoxic group. The gills exhibited increased NKA protein expression in the hypoxic and restricted groups, respectively. Functional plasticity in CAII and NKA protein expressions was found between the gills and the labyrinth organ in adult M. opercularis.

Axenic cultures of two moss taxa viz. Bryum dichotomum Hedw., an acrocarpous moss and Entodon macropodus (Hedw.) Mull. Hal., a pleurocarpous moss were established by inoculating their spores into agar media. Germination, growth, development and comparative morphogenetic studies of these two growth forms were done. In B. dichotomum, protonemal buds developed on caulonema, while in E. macropodus, buds were produced on chloronema. Sub culturing of B. dichotomum gave rise to new individuals through chloronemal and caulonemal stage, while E. macropodus it directly regenerated into new gametophytes. In old culture under low moisture conditions, asexual diaspores namely, protonemal bulbils B. dichotomum and protonemal brood cells E. macropodus were formed.

Aquarium trade has been the source of many alien species being introduced into the natural waters of Chennai. Trichopsis vittata and Macropodus opercularis are being reported for the first from Chennai. However, contrary to the propagule pressure theory both these species are not common in the aquarium trade, raising speculations of inter-basin water transfer playing a role in introducing non-native species into an ecosystem.

Macropodus opercularis is a popular ornamental fish and has been widely transported around the world. In this study, the complete mitochondrial genome of M. opercularis was reported. The circular genome is 16,496 bp in length and consists of 13 protein-coding genes, 22 tRNA genes, two ribosomal RNA genes, and one control region. The overall nucleotide composition was 30.9% A, 29.6% T, 24.7% C, and 14.8% G, with an A + T bias of 60.5%. The gene composition and the structural arrangement of the M. opercularis complete mtDNA were identical to most of the other vertebrates. The molecular data presented here could play a useful role in studying the evolutionary relationships and population genetics of Macropodusinae fish.

The Siamese fighting fish (Betta splendens) is one of the popular aquarium fish. Serious attentions have been paid to the biodiversity of the fish. The mitochondrial genome of the Siamese fighting fish is reported to be 17 099 bp and includes 37 genes. The gene organization is similar to other fish mitogenomes. The control region is AT-rich and includes three tandem repeats. Phylogenetic analysis reveals that the fish is close to fish in the Macropodus genus. This mitogenome will assist in studying the mitochondrial variations and population structure in this fish and examine the evolutionary relationship among fish in the Osphronemidae family.