Biochemical changes of cryopreserved seminal plasma and spermatozoa of the giant grouper Epinephelus lanceolatus after preservation and transportation using dry-ice

The present study aims to investigate the effects of exposure of the seminal plasma and spermatozoa of the giant grouper Epinephelus lanceolatus to dry ice ( 79 C) during transport on their quality. In all, 15 amino acid compounds were determined. The quantification of total proteins were measured using the Bradford method, and amino acid concentration were measured using the HPLC method. The cryopreserved seminal plasma was transferred from a liquid nitrogen tank to a styrofoam box filled with dry ice. Total protein and amino acids were measured after 24, 48, and 72 h. For comparative purposes, total protein and fifteen compound of amino acid were also measured. Both parameters were also measured after the cryopreserved seminal plasma were immersed in liquid nitrogen after 24 and 48 h exposed to dry ice. The results showed that the exposure of seminal plasma to dry ice for 24, 48 and 72 h during transportation or immersion back into the liquid nitrogen after 24 and 48 h does not change the total protein levels either in seminal plasma or spermatozoa. However, the level of each amino acid compound in the seminal plasma had significantly decrease

Optimization of the cytogenetic protocol for Pangasianodon hypophthalmus (Sauvage, 1878) and Clarias gariepinus (Burchell, 1822)

To obtain well spread chromosomes, the cytogenetic protocol for Pangasianodon hypophthalmus and Clarias gariepinus were optimized. This includes, the colchicine concentration (0.01%, 0.025%, 0.05%)/exposure duration (1, 3, and 5 h), hypotonic solution (distilled water or 0.075M KCl solution)/exposure duration (30 min, 1, and 2 h), the time of cell suspension preparation (at hypotonic treatment or before slide preparation) and chromosome aging period (0, 3, and 7 days in Carnoy’s fixative). In addition, the type (i.e., fin, gill or kidney) and the amount of tissue (10, 50, 100 or 150 mg) were also investigated. Regardless of the species, the result obtained showed that well-spread chromosomes could be obtained using the following optimized protocol: Juveniles are injected with 0.05% colchicine (at one ml kg−1) and allowed to swim for 3 h. Then, 50 mg of gill tissue is made into cell suspension in 0.075M KCl for 1 h. The cell suspension is treated in Carnoy’s fixative (changed three times at 20 min interval) and then aged for 3 days. Finally, chromosome slides are made and stained with 10% Giemsa for 1 h

Dataset for the morphological and erythrocytes parameters of Clarias gariepinus, Pangasianodon hypophthalmus, and their reciprocal hybrid

Discrimination of different fishes can be done through different means which includes morphological appearance. When two fishes are successfully hybridized, they produce progenies that have shared morphology between their pure parent, hence, making morphometric characterization an important aspect of hybrid discrimination. However, erythrocyte characterization is also a simpler method for characterization. The dataset presented in this article represents the traditional morphological data, truss network data and erythrocyte data of pure and novel hybrids from reciprocal crosses of African catfish Clarias gariepinus and Asian catfish Pangasianodon hypophthalmus. Breeding of the broodstocks was done to produce pure and hybrid progenies which were maintained for a period of four to six months. Based on the cross combinations and morphotypes, traditional measurement of twenty-five morphological characters and five meristic counts were recorded. Thereafter pictures of the different fish groups were used to determine values of thirty-six distances between ten landmark points. The morphological abnormality of the hybrids at market size is also presented in this data article for the very first time. Blood was then collected from the caudal peduncle of ten fish per group and smeared on a slide for observation under a compound microscope (at 100 × magnification). Data gotten included erythrocytes parameters such as cell major axis, cell minor axis, nucleus major axis, nucleus minor axis cell area, nucleus area, cell volume, and nucleus volume. Data recording was through the Microsoft excel spreadsheet; which was also used to process the data to get the exclusive ranges of values for paired progenies. The data as presented is associated with the research article “Morphological characterization of the progenies of pure and reciprocal crosses of Pangasianodon hypophthalmus (Sauvage, 1878) and Clarias gariepinus (Burchell,1822)” [1].The dataset presented in this article can be used for easy identification of the novel hybrid progenies of the African Catfish and Asian Catfis

DNA barcoding of Arius species (Siluriformes: Ariidae) found in Peninsular Malaysia waters, using mitochondrial Cytochrome oxidase subunit I gene.

Ariid catfishes are widely distributed in tropical and temperate continental shelves all over the world, mainly inhabiting inshore waters and estuarine regions, or in some cases confined to freshwaters. Ariid catfishes, commonly known as the sea catfishes, belong to family Ariidae (order: Siluriformes). Ariids are one of the problematic groups for the identification using their morphological features. Furthermore, keys available for the identification are unclear and confusing. Thus, this study was done in order to determine the species in one of the problematic ariid’s genera, Arius, which found in Peninsular Malaysian waters using molecular approach. There were four species of Arius found in this study, Arius leptonotacanthus, Arius maculatus, Arius oetik and Arius spp. All the species were sequenced for 499-bp region of the mitochondrial cytochrome oxidase subunit I (COI) gene. Five sequences per species were amplified and a neighbour-joining phylogenetic tree using Tamura-3 parameter (T92+G) model was constructed. The results shows that Arius leptonotacanthus formed the base for other Arius species (A.maculatus, A.oetik and Arius spp.) supported by a moderate bootstrap value of 50%. Whereas, Arius maculatus formed a sister taxa to Arius spp. with 91% of bootstrap value. Overall, the phylogenetic tree shows that all the Arius species were grouped in separate clades according to the respective species with the support of high bootstrap values. Thus, this study revealed that this problematic Arius species can be clearly differentiated using the molecular marker

Morphological variations of plicofollis species (Siluriformes: Ariidae) in Peninsular Malaysia: an insight into truss network Approach

Ariid catfishes, belong to family Ariidae is considered as one of the taxonomically problematic groups, which is still under review by fish taxonomist globally. Species level identification of some ariids often resulted in species misidentification because of their complex characters and very similar morphological characters within genera. A vigilant and detail observation is very important during the species level identification of ariid species. In these contexts, this study was carried out in order to determine the morphological variations of one of the ariid genera, Plicofollis, which have been giving misleading taxonomic information in the south-east Asian countries. A Truss network technique was used throughout the study period. The study was conducted based on 20 truss measurements using 22 to 23 specimens per species, namely P. argyropleuron, P. nella and P. tenuispinis found in Peninsular Malaysian waters. Morphological variations were determined using a multivariate technique of discriminant function analysis (DFA). The results obtained in this study showed that discriminant analysis using truss network measurements has produced very clear separations of all the species in Plicofollis group. Several important morphological characters have been identified, which represent body depth and caudal regions of the fish. The documentary evidences of these variables could be considered as the constructive functional features, which could enable us to assess more accurately to distinguish the species within this complex Ariidae family

Morphometric Variations Between Triploid and Diploid Clarias gariepinus (Burchell, 1822)

Several scientific methods have been described in the identification of triploid fish. However, many of these methods are not applicable for routine management purposes due to their complexity and cost. In this study, the possibility of using morphological variation as a least cost and less complex method of distinguishing triploid and diploid African catfish Clarias gariepinus (Burchell, 1822) was examined. Triploid catfish were produced by cold shock of fertilized eggs in 5°C for 20 mins (at approximately 3 mins after fertilization). The fish were incubated, hatched and raised for 3 months. Ploidy levels of the fish were then ascertained by observing the erythrocyte shape. Triploid erythrocyte was ellipsoidal in shape while diploid was round. Morphological characterization was then carried out on 100 samples each of triploid and diploid African catfish. Although significant differences were observed in many parameters, the principal morphometric difference between triploid and diploid African catfish could not be clearly distinguished. It was therefore concluded that morphological characteristics is not ideal for discriminating triploids and diploids of African catfish. The used of erythrocyte characteristics still remains the cheapest and relatively effective method for triploid and diploid determination in African catfish

MORPHOMETRIC VARIATIONS BETWEEN TRIPLOID AND DIPLOID Clarias gariepinus (Burchell, 1822)

Nekoliko znanstvenih metoda ranije je opisano za prepoznavanje triploidnih riba. Međutim, mnoge od tih metoda nisu primjenjive u svrhu rutinskog upravljanja radi njihove složenosti i troškova. U ovom radu istraživana je mogućnost korištenja morfoloških varijacija kao jeftine i jednostavne metode razlikovanja triploidnih i diploidnih afričkih somova Clarias gariepinus (Burchell, 1822). Triploidski somovi su proizvedeni metodom hladnog šoka oplođenih jaja na 5°C tijekom 20 minuta (približno 3 min. nakon oplodnje). Ribe su bile inkubirane, izvaljene i uzgajane tijekom 3 mjeseca. Plodnost riba utvrđena je promatranjem oblika eritrocita. Triploidni eritrocit bio je elipsoidnog oblika dok je diploidi bio okrugli. Morfološka karakterizacija je provedena na 100 uzoraka triploidnih i na 100 uzoraka diploidnih afričkih somova. Iako su značajne razlike zabilježene u mnogim parametrima, glavna morfometrijska razlika između triploidnih i diploidnih afričkih somova nije se mogla jasno razlikovati. Stoga je zaključeno da morfološka svojstva nisu idealna za razlikovanje triploida i diploida afričkog soma. Upotreba eritrocitnih karakteristika i dalje je najjeftiniji i relativno učinkovit način za triploido i diploidno određivanje afričkih somova.Several scientific methods have been described in the identification of triploid fish. However, many of these methods are not applicable for routine management purposes due to their complexity and cost. In this study, the possibility of using morphological variation as a least cost and less complex method of distinguishing triploid and diploid African catfish Clarias gariepinus (Burchell, 1822) was examined. Triploid catfish were produced by cold shock of fertilized eggs in 5°C for 20 mins (at approximately 3 mins after fertilization). The fish were incubated, hatched and raised for 3 months. Ploidy levels of the fish were then ascertained by observing the erythrocyte shape. Triploid erythrocyte was ellipsoidal in shape while diploid was round. Morphological characterization was then carried out on 100 samples each of triploid and diploid African catfish. Although significant differences were observed in many parameters, the principal morphometric difference between triploid and diploid African catfish could not be clearly distinguished. It was therefore concluded that morphological characteristics is not ideal for discriminating triploids and diploids of African catfish. The used of erythrocyte characteristics still remains the cheapest and relatively effective method for triploid and diploid determination in African catfish

Morphological descriptions and morphometric discriminant function analysis reveal an additional four groups of Scylla spp

There are four species of mud crabs within the genus Scylla, and most of them live sympatrically in the equatorial region. Apart from a report in Japan about the finding of a natural Scylla hybrid more than a decade ago after the division of genus Scylla into four species by Keenan, Davie & Mann (1998), no subsequent sighting was found. Thus, this study investigates the possible natural occurrence of potential hybridization among Scylla species in the wild. A total of 76,211 individuals from mud crab landing sites around the Malacca Straits, South China Sea and Sulu Sea were screened. In addition to the four-purebred species, four groups (SH 1, n = 2, 627; SH 2, n = 136; SH 3, n = 1; SH 4, n = 2) with intermediate characteristics were found, mostly at Sulu Sea. Discriminant Function Analysis revealed that all Scylla species, including SH 1 - 4, are distinguishable via their morphometric ratios. The most powerful discriminant ratios for each character and the top five discriminant ratios of males and females were suggested. The carapace width of SH 1 males and females were significantly smaller than pure species. Based on the discriminant ratios and the description of morphological characters, we hypothesize that the additional four groups of Scylla with intermediate characteristics could be presumed hybrids. Future work at the molecular level is urgently needed to validate this postulate