International Journal of Aquatic Biology
Volume:12 Issue: 1, Feb 2024

We report a detailed description of the vertebral column of the giant trevally (Caranx ignobilis, Forsskål 1775). A total of 10 giant trevally were obtained from the Jangka seawaters, Bireuen Regency, Aceh Province, Indonesia. The giant trevally vertebral columns were processed physically and chemically. The vertebral column was disarticulated and observed individually. Morphometric parameters were measured, including the length, width, and height of the centrum, the length of the rib, the length of the neural spine, and the length of the haemal spine. The results showed that the vertebral column of the giant trevally consisted of three regions, namely the abdominal vertebrae, the caudal vertebrae, and the urostyle. The abdominal region comprises 10 centra, 7 pairs of costae, 10 neural spines, and 4haemonephropophysis. The caudal region comprises 13 centra, 13 neural spines, 13haemal spines,and 1haemonephropophysis. The urostyleregion is composed of 2hypurals,1parhypural, 1uroneural,and1epural. Morphometrically, the length and height value of the centrum of the giant trevally were greater than the width. The 4thcostae, 14thneuralspines,and 11thhaemalspines werealso observed to be the longest compared to others in their respective series.

Bacterial disease is a major problem in Pacific whiteleg shrimp, Litopenaeus vannamei farming areas where farmers are facing a huge production loss due to epidemic diseases. The incidence of running mortality syndrome (RMS) was reported in L. vannamei, in an intensive biofloc culture system. Infected shrimps showed bacterial spots on the surface of the carapace, thick transparent mucous attached to the hepatopancreas, antennal cut, and cannibalism. Microscopical examination revealed a lichen-like structure with undulated margins varying about 22-650 µm size. Morphological characteristics of the colonies were smooth, circular, and opaque. Histopathological studies showed the sloughing of the tubule, multiplication of the bacterial plaque, and infiltration of the hemocytes in the infected hepatopancreas. Scanning electron microscopy of the infected shrimp revealed bacilli and cocci-shaped bacteria. Using transmission electron microscopy, bacterial populations were observed in the cytoplasm.

The grass puffer, Takifugu alboplumbeus, a euryhaline fish species, was collected from both river and marine environments, and the gut microbiota of these specimens was examined using clone library analysis and qPCR technology. The results indicated that Aliarcobactersp. constituted 27.3-96.9% of the three 16S rDNA libraries for river pufferfish and 40.6-86.8% of the three libraries for saltwater pufferfish, indicating that this bacterium is the dominant organism in both river and saltwater pufferfish. Furthermore, Brevinemasp., Mucinivorans sp., Mycoplasma sp., Pseudomonas mosselii, and unclassified members of Desulfovibrionaceae family were detected in both river and saltwater pufferfish at frequencies of 50-83%. In contrast, Ilumatobacter fluminis, Ilumatobacterspp.,Nitrincolasp., Tropicibacter alexandrii, and unclassified members of the Microthrixaceae and Mycoplasmataceae families, as well as the Mollicutes class, were detected only from river pufferfish, while Vibriospp. were detected only in two out of three libraries of saltwater pufferfish. However, qPCR for Vibrionaceae showed that the abundance of Vibrionaceae in the gut of river pufferfish was significantly lower than in saltwater pufferfish,although neither was the predominant bacteria. These results indicate that river and saltwater pufferfish have different gut microbiota. This suggests that the differences in the gut microbiota between river and saltwater pufferfish may be related to the differences in salt tolerance of the gut bacteria, as well as the differences in the environmental microbiota of river and marine waters.

The study was conducted in the Al-Dalmaj marsh which is one of the most important ecosystems in Iraq and the Middle East and represents one of the most important environments for the reproduction of Marbled Teal. The study evaluated the accumulation of heavy elements of Nickel, Cadmium, and Lead in the liver and small intestine tissues of MT during the summer and winter. The results showed that the concentration of heavy metals in the MT organs is consequent as small intestine > Liver. The average concentration of Ni was the highest as 6.6973 ppm in the small intestine, and the highest percentage was recorded at 4.3272 ppm in the liver during the summer. The highest cumulative rate of the element during both seasons was 5.95±0.54 in the intestine, and 1.1681 ppm was the highest rate of Cd in the liver during summer, and 0.9308 ppm was the highest concentration in small intestine during winter. The highest cumulative rate of concentration of elements in the liver during both seasons was 0.982±0.27 ppm. The highest level of Pb was 8.0715 ppm in summer, and 7.566 ppm in the small intestine. The highest cumulative average of the element during both seasons in the small intestine was 6.93±0.55 ppm.

This study aimed to describe the distribution and diversity of soft bottom mollusk community in the Syrian transitional region and to assess the state of alien species in the northern part of the Syrian coast north of Latakia (Ibn Hani site) since 2010, at depths ranging between 110-160 m. Sixty benthic samples were collected monthly using a Van-Veen grab 1/40 m2. Water temperature, salinity, pH, and dissolved oxygen of the subsurface water were measured. Molluscan specimens were isolated and identified at the species level. The abundance and biomass for each species in the samples and per square meter were considered to assess spatial and temporal variation of Molluscan assemblages between depths within the months. A total of 167 mollusk species belonging to 3 classes were identified, 57 newly recorded in Syria, and 18 (10.7%) non-indigenous species were found. Among these, three new aliens of Retusa truncatula, Styloptygma beatrix, and Afrocardium richardi were recorded for Syria. The presence of these mollusks was associated with the soft sediments (mud), which did not differ by time or depths. The results revealed that the Molluscan community was dominant by Bittium arenarium, B. tarentinum, Odostomia   lorioli, Turritella turbona, Varicorbula gibba, Nucula nucleus, and Lembulus pella. A significant decrease in biomass is expected due to overfishing and severe nutrient deficiency. Our study adds a large number of mollusks to the list of previously recorded species and confirms the increase in the number of aliens and the expansion of their spread in the medium depths. Greater efforts are required to detect more aliens and evaluate their progress, spread, and their relationship with natives, especially in harbors and port environments.

The study aimed to determine the water quality of the Al-Sabil River using the Canadian Water Quality Index (CCME WQI). The study was performed by measuring some physical and chemical properties in four selected sites that extend in three provinces including Najaf, Al-Diwaniyah, and Al-Muthanna for a distance of 114 km for six months from August 2022 to January 2023. The results revealed that the average physical and chemical properties, including water temperature, pH, and EC were 19.33-25.33?, 7.25-7.54, and 1138-2510 µs/cm, respectively. The total suspended solids and turbidity recorded 1261-1676, 30.1-47.78, respectively. The DO and BOD have been recorded at 6.417-7.1, and 3.467-6.133 mg/L respectively. The total hardness, Ca, and Mg were 630-853.3 mg/L, 146.3-192.7 mg/L, and 87.39-236.19 mg/L, respectively. The phosphate, nitrite, and nitrate (mg/L) were 0.591-0.887, 0.486-1.539, and 1.772-6.921, respectively. The results of the study using the Canadian model water quality index (CCME WQI) showed that the lowest rate was 44.35 showing a poor condition in the first site and the highest rate was 51.41 as a marginal condition in the 3rd site.