The Effectiveness of Turmeric Enriched Pellets in Curing the Gill of Clarias batrachus Infected with Aeromonas hydrophila

Curcumin is an antibiotic agent extracted from Curcuma longa. To understand the effectiveness of curcumin in curing the gill of Clarias batrachus infected with Aeromonas hydrophila, a study was conducted from August to November 2020. There were 3 treatments applied, namely turmeric enriched pellets 0.7g/kg (P1); 0.9g/kg (P2) and 1.1g/kg (P3). Prior to the treatment, the fish was infected with A. hydrophila (0.1 m of A. hydrophila culture, 1.0x108cells/ml). The infected fish was kept for 6 days until the clinical signs of MAS disease occurred. By the 7th day, the fish was feed with turmeric enriched pellets. For negative control (Cn) the fish was not infected with A. hydrophila nor treated with turmeric, while the positive control (Cp) was infected, but no turmeric treatment. The fish was reared for 30 days and by the end of the experiment, the gill was removed and processed for histological study (5L sliced and HE stained). Result indicated that the gill of the negative control fish was normal, while that of the positive control shown abnormalities such as hemorrhages, necrotic cells, fused lamellae and enlarged cartilaginous cells. The turmeric treated fish shown less damage in the gill. The best results were obtained in C3, as the gill structure was almost normal with slightly hemorrhage. In the C1 and C2 treated fishes, the gill shown light abnormality such as fused lamella and hemorrhage. Data obtained shown that the consumption of turmeric enriched pellet was effective to cure the A. hydrophyla infected gill.

Gill Histopathology as a Biomarker for Discriminating Seasonal Variations in Water Quality

Histopathological alterations in various fish organs have a pronounced value in aquatic toxicology and are widely used in environmental monitoring. The aim of this study was to evaluate whether histopathological alterations in fish gills can discriminate seasonal variations in environmental conditions within the same aquatic ecosystem, and if so, which alterations contributed the most to seasonal differentiation. Microscopic examination of common bream Abramis brama gills displayed various alterations in gill structure, including epithelial hypertrophy, hyperplasia, mucous and chloride cell alterations, epithelial lifting, necrosis, hyperemia and aneurism. These alterations were subsequently quantified by a semi-quantitative analysis in order to detect differences in the intensity of the mentioned alterations. Epithelial hypertrophy, hyperplasia, epithelial lifting and necrosis varied significantly between seasons with only necrosis being significantly higher in the first season. Discriminant canonical analysis displayed that epithelial hyperplasia, mucous cell alterations, epithelial lifting and necrosis contributed the most to discrimination between seasons. Overall, this study demonstrates that histopathological biomarkers in fish gills can be used in discriminating seasonal variations in water quality within the same aquatic ecosystem.

Effects of short-term salinity exposure on haemolymph osmolality, gill morphology and Na+/K+ - ATPase activity in Solenaia oleivora

In order to explore the physiological reaction to hyperosmotic environment, Solenaia oleivora were exposed to 2.23‰ salinity. In 48h, the hemolymph osmolality kept increasing, and the hemolymph protein concentration increased in the first 6h and then decreased significantly, while the free amino acid content increased in the first 24h and then kept stable (P < 0.05). The activity of Na+/K+-ATPase at 0h was significantly higher than other times in most organs except intestine, which was highest at 3h (P < 0.05). The ions concentration were also influenced. The concentration of Na+ rose in haemolymph, axe foot and intestine, but decreased in gill and hepatopancreas. In hemolymph, gill, hepatopancreases and adductor muscle, the K+ concentration was the highest at 0h, while in axe foot and intestine, it showed a positive tendency. The concentration of Cl- in haemolymph, adductor muscle, intestine and axe foot were positively correlated with treatment time, while hepatopancreas showed opposite tendency. High salinity stress caused a difference in the gill histological structure, the gill structure shrunk, the gill lamellas space and shrinking degree showed an enlarging trend with salinity treatment time.

A rare new species of Leptohyphes Eaton (Ephemeroptera: Leptohyphidae) from the Lost World

A new species of Leptohyphes Eaton (Ephemerotera: Leptohyphidae) is described, diagnosed and illustrated from nymphs collected in the Pantepui region in Southeastern Venezuela. Leptohyphes kukenan sp. nov. is similar to Leptohyphes populus Allen because they share a unique character for the genus: male compound eyes are divided. Other unique characters for the new species include a plesiomorphic gill structure, with imbricated ventral lamellae, and paired subapical denticles on tarsal claw. The new species show a unique combination of characters that distinguish it from L. populus and all other species of Leptohyphes: fore and hind margin of femora with spines on strong elevated sockets, part of body and legs covered by small pale spots, tarsal claws with 4–5 marginal denticles and a subapical pair of submarginal denticles, pronotum with large rounded lateral projection, hind wing pads absent in female, gill formula 8/7/7/4/1, operculate gill with imbricated ventral lobes, and gill V without ventral extension on dorsal lamella.

The potential respiratory surfaces of a fish living in a historically polluted river

The acquisition of oxygen is fundamental for maintaining metabolic activity in fish, and most species obtain oxygen through aquatic gill respiration. Throughout evolution, different fish lineages have evolved secondary routes to obtain oxygen from atmospheric air, and the spinycheek sleeper, Eleotris pisonis, may be one example of such bimodal respiration. Gill structure and the top epithelium of the head of E. pisonis from the Subaé River (Santo Amaro, Bahia, Brazil) were evaluated morphometrically. The gills showed histopathologies, especially proliferation, which was prevalent on 35.6% of the filaments and on 13.7% of the lamellae, probably increasing the water-blood diffusion barrier of the lamellae to 5.48 ± 1.32 μm, similar to the air-blood diffusion distance of the skin (5.77 ± 1.72 μm). Quantitative morphometric analysis of histopathologies and diffusion distances could be considered as biomarkers, and also suggest the presence of cutaneous respiration as a possible strategy for aerial oxygen acquisition.

The evolution of water-breathing respiratory faculties in craniotes

The major components of the respiratory faculty (gill structure, muscular ventilation, central heart and erythrocyte-containing blood, and pH-sensitive control of breathing) appear to have been present in craniotes from the very beginning. But the details are so different in the most basally radiating group, hagfish, corroborating that they separated very early from the stem line. In the other groups, progressive changes are seen in the structure of the gills, heart, haemoglobin, as well as in the control of breathing. In particular, a major and progressive change in gill structure is seen when comparing sharks to teleosts, with several intermediary forms realized.

Histological Study of Mudskipper (Periophthalmus gracilis) Gills

Mudskipper belongs to the Gobiidae family which has respiratory adaptation to fits their habitat. Mudskipper has a different gill structure or modification of gills, this different structure allows the mudskipper to survive for a long time outside water. This study aimed to determine the histology of gills and find out whether there is a modification of gills in the mudskipper respiratory organs (Periophthalmus gracilis). Histological preparations were done using paraffin method, stained with Hematoxylin-Eosin. Data analysis was carried out in a qualitative descriptive. The results showed that there is no additional respiratory organ in the mudskipper respiration, whereas the gills have some modifications. The histological structure of mudskipper gills consists of gill arches, arteries, gill filament, primary lamellae, and secondary lamellae. The gills of mudskipper have a different structure from the general fish, which has a thick secondary lamellae with a low amount of density, the shape of the filament are short and bent. This gill structure is a form of adaptation to habitat and behavior to live outside the water in a relatively long time.

Comparative Anatomy of Labyrinth and Gill of Catfish (Clarias gariepinus) (Burchell, 1822) and Snakehead Fish (Channa striata) (Bloch, 1793)

Dumbo catfish (Clarias gariepinus) and Gabus (Channa striata) have additional organ respiratory system structures in the gills, called labyrinth. This organ is a tool for fish to take oxygen directly from the air so that it can live in low oxygen habitats. Both fish have differences at the Order level. Catfish is an order of Siluriformes as Gabus is an order of Perciformes. The purpose of this study was to distinguish the anatomy and histology of the gill structure and labyrinth in both fish. The macroanatomy observation was conveyed by dissection to determine the gill topography in the two fish species. Histology preparations were carried out using the paraffin method and using Hematoxylin-Eosin (HE) staining that showed in the labyrinth organ there were many blood vessels to bind oxygen then distributed to all parts of the fish's body.