Full Text Available The intricate process of spermatogenesis in the paradise fish, Macropodus opercularis, was studied. In this species, the unrestricted or lobular type testes lining the caudal side of the body cavity are translucent and slender. Spermatogonia occur along the length of the tubules and the development of sperm takes place within cysts formed by Sertoli cells. Spermiogenesis involves preparatory morphological events followed by conspicuous modifications such as the movement of the centrioles, completion of the nuclear condensation, reduction of the cytoplasm, and the final differentiation of the flagellar complex. Mature spermatozoon has an oval nucleus, condensed chromatin, and typical 9 + 2 flagellar axoneme but lack acrosome. The role of the material in the nucleus and the cytoplasm as it reaches the Sertoli cell in the control of spermatogenesis is discussed.
Ho Anh TUAN
Full Text Available Analysis and identification of 57 specimens of genus Macropodus Lacépède collected from Gianh River in Quang Binh province in north center region Vietnam. We have classified three species: Macropodus erythropterus (Frey. & Her., 2002, Macropodus opercularis (Linneaeus, 1758, Macropodus spechti (Schreitmüller, 1936 was first discovered in the study area and north center region Vietnam.CARACTERISTICA MORFOLOGICĂ PENTRU CLASIFICAREA GENULUI MACROPODUS LACÉPÈDE, 1801 DIN BAZINUL RÂULUI GIANH, REGIUNEA CENTRALĂ DE NORD A VIETNAMULUIAu fost analizate şi identificate 57 de exemplare ale genului Macropodus Lacépède colectate din bazinul râului Gianh, provincia Quang Binh, regiunea centrală de nord a Vietnamului. Noi am clasificat 3 specii: Macropodus erythropterus (Frey. & Her., 2002, Macropodus opercularis (Linneaeus, 1758 şi Macropodus spechti (Schreitmüller, 1936, descoperite în aria de studiu şi în regiunea centrală de nord a Vietnamului.
Huang, Chun-Yen; Lin, Cheng-Huang; Lin, Hui-Chen
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. Copyright © 2015 Elsevier Inc. All rights reserved.
Csányi, V; Gervai, J
Passive dark avoidance conditioning and effects of the presence and absence of a fish-like dummy on the training process were studied in four inbred strains of paradise fish. Strain differences were found in the shuttle activity during habituation trials, and in the sensitivity to the mild electric shock punishment. The presence or absence of the dummy in the punished dark side of the shuttle box had a genotype-dependent effect on the measures taken during the conditioning process. The statistical analysis of the learning curves revealed differences in the way the strains varied in the different environments, i.e. genotype--environment interaction components of variances were identified. The results are discussed in the light of previous investigations and their implication in further genetic analysis.
Gerlai, R; Csányi, V
The behaviour of the paradise fish in a traditional "closed" and in a new "transparent" open-field was investigated. The traditional way of measuring ambulation scores was extended by recording ethologically defined behaviour units. The correlations found between the scores measured in the "closed" field and those measured in the "transparent" field are discussed in this paper.
J.D. Marcus Knight
Full Text Available 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.
Levsen, Arne; Berland, Bjørn
In this paper, the quantitative post-embryonic development of the Asian freshwater fish nematode Camallanus cotti Fujita, 1927, is described. Larval and adult morphometrics were obtained by following the parasite's life cycle experimentally using copepods Macrocyclops albidus (Jurine) as intermediate host and guppies Poecilia reticulata (Peters), southern platyfish Xiphophorus maculatus (Günther) and paradise fish Macropodus opercularis (L.) as definitive host. Additionally, adult worms were obtained from heavily infected paradise fish imported from Singapore. It is suggested that the gradual change in proportions of the worm's somatic body parts reflects the specific ecological role of each developmental stage. The free-living infective first-stage larva seems to be adapted for transmission, as indicated by its relatively long tail, designed to generate host-attracting movements, and its non-functional intestine. The second- and third-stage larvae from the copepod intermediate host seem mainly to invest in trophic functionality, i.e., the development of the buccal capsule and the oesophagus, which are crucial structures for the worm's successful establishment in the definitive fish host. Once in the fish intestine, the larvae enter a period of considerable growth. After the fourth (i.e., last) moult, a 72% increase in average female body length occurs. This is accompanied by doubling the average vulva-tail tip distance and the average tail length. The length of the female hind body expands in an accelerating allometric fashion, and seems to be closely linked to the posterior-wards expansion of the uterus. In the males however, growth seems to cease after the final moult. We conclude that female post-maturational body size, but especially the length of the hind body and the tail, are closely related to reproductive state, i.e., the developmental stage of the offspring in the uterus, and, probably, the worms' age. Any future taxonomical studies of camallanids in