Centropagidae is comparatively a larger family to other families of order calanoida. The ‎quantitative data revealed that the copepods of the genus Centropages are the ‎dominant component in the zooplankton samples from the designated station in ‎Sonmiani bay, a coastal lagoon at Balochistan coast, northern Arabian sea. Four ‎epipelagic species of family Centropagidae, Centropages (Centropages dorsispinatus ‎Thompson I.C. & Scott A., 1903, Centropages tenuiremis Thompson I.C. & Scott A., ‎‎1903, Centropages furcatus (Dana, 1849) and Centropages orsinii Giesbrecht, 1889 ) ‎were identified. Male and female specimens were distinguished on their characteristic ‎features of antennules, thoracic segments and fifth legs. Identified specimens were ‎described briefly with their microscopic illustrations. Centropages dorsispinatus and ‎Centropages tenuiremis were frequently found in zooplankton samples throughout the ‎sampling season.‎

The current study illustrates the life-history traits; including length frequency distribution ‎‎(LFD), length-weight and length-length relationship (LWR and LLR), condition factors ‎‎(allometric, KA; Fulton’s, KF; relative condition, KR; relative weight, WR), and natural ‎mortality (Mw) of Lates calcarifer from the Bay of Bengal, Bangladesh. A total of 103 ‎individuals were randomly collected from January to December 2021 using traditional ‎fishing gear including Koral net and gill net. For each individual, total length (TL), ‎standard length (SL), and total body weight (BW) were measured with measuring scale to ‎‎0.1 cm and digital balance to 0.1 g precision, respectively. The TL size class 84.0 cm was ‎a numerically dominant group in the population. The b value of LWR (TL vs. BW) ‎indicated positive allometric growth (b=3.28) pattern in the Bay of Bengal. Likewise, the ‎b value of LLR indicated also the same growth pattern. Among the four types of ‎condition factors, KF is the best-suited tool for evaluating the well-being of L. calcarifer. ‎Additionally, WR exhibited significant divergence from 100 (P< 0.0001), defining an ‎imbalanced habitat. The calculated Mw was 0.23 year-1 for L. calcarifer. Therefore, these ‎findings would be used in the future for the improved management of this species in the ‎Bay of Bengal as well as for connecting ecosystems.‎

This study evaluated the effects of freezing periods on nutritional values, microbial ‎loads, and some pathogenic bacteria in Nile Tilapia (Oreochromis niloticus). 8 kg.‎‏ ‏Samples were collected from El-mawourda Fish Market in Khartoum State, for four ‎experimental treatments. The treatments were conducted on the period 0 day, 7 days, 15 ‎days and 21 days.‎‏ ‏It is noticed that the freezing period effect on the nutritional value, ‎microbial load and some pathogenic bacteria of Nile tilapia (Oreochromis niloticus) ‎revealed that the lowest average nutritional assessment of Nile tilapia (Oreochromis ‎niloticus) observed for protein 20% at the third period of freezing (21 days), and ‎minerals were calcium, phosphorus, magnesium, iron, sodium and potassium (5.6 – ‎‎2.7%, 4.8 – 2.9%, 2.6 – 2.9%, 1.1 – 0.71%, 4.5 – 2.8%) respectively. The‏ ‏result of this ‎study clarified that the freezing period has a considerable consequence (p ≤ 0.05) on the ‎chemical composition, microbial load and same pathogenic bacteria (E. coli and ‎Salmonella) of Nile tilapia (Oreochromis niloticus).‎

Sarda orientalis (Family-Scombridae) of assorted length (cm) and weight (gm) were obtained from Karachi fish harbor during January to December (2019) for measurement of length-weight relationship (LWR’s) and Fulton‘s condition factor (K). The range of length (57-60.8) and weight (2123-2641) were estimated. Total mean length (cm) (gm) (59.14±0.94) and weight (gm) (2336.32±114.21) were measured. LWR was estimated as W = 0.08166134 × L 2.5149 (log W = -1.088 + 2.5149log L). The highest mean of condition factor (K) (1.15±0.02) were measured in post-monsoon season. Assorted (ANOVA) analysis indicates that there is a significant correlation between weight, length, and season (p0.05).

Lake Borollus is one of the largest and oldest Egyptian lakes, whereas it is located in the ‎far north of the Delta and mediates between the two branches of Rosetta and Damietta. ‎It is connected to the Mediterranean Sea through Boghaz El Borollus and to the Nile ‎through the Bermbal Canal, which was established in 1926 to feed the lake with ‎abundant quantities of Nile water and Nile fish. Central coordinates: latitude 31°30' N ‎and longitude 30°49' E with an area has decreased from 160,000 acres to 108,000 acres. ‎The present work provides an ecological study on the regional and temporal distribution ‎of benthic communities in particular along the wetlands lakes waters. Indicated that, the ‎effective sediment and water variables which significantly correlated with the distribution ‎and abundance of the identified benthos assemblages of vegetation and animal’s groups ‎include sediments structure, water quality (pH, S%, DO, BOD, temperature. Overall, 10 ‎taxa and 27 species of macroinvertebrates were identified. They were exclusively ‎associated with submerged vascular plants Potamogeton pectinatus while only 10 were ‎alive forms and the rest were represented by calcareous shells of molluscs. The benthic ‎flora and fauna were estimated in the Lake Botollus, Egypt is subjected to the influx of ‎sewage effluents, agriculture drainages and industrial wastes. Also considerable amounts ‎of drain water are constantly discharged along the southern drains. Quantitative hauls ‎were performed at the different habitats during winter and summer, 2017 covering 12 ‎sampling sites and 9 drains discharged directly to the lake which bottom sampling was ‎collected by grab sampler were selected to represent the covering the different ‎environments. The dredged area per each station was 225 cm2 per haul. Results ‎illustrated that the distribution of benthos in the estimated area is greatly affected by the ‎degree of pollution as well as the prevailing hydrological conditions. The aquatic ‎submerged vascular plants Potamogeton pectinatus appeared as the most common ‎species in the lake in addition the bottom animals appeared more- sensitive to pollution ‎than submerged vascular; thus, their lowest counts were recorded at the most sites and ‎the fauna was mainly represented by the Nematoda, Oligochaeta, Polychaeta, Insects ‎larvae, Ostracoda, Amphipoda, Barnacles, and juvenile larvae of Mollusca. Sediments in ‎some areas consist of organic materials (sludge) is composed of waste sewage and ‎agricultural and industrial and others of sandy silt (silt), calcareous shells are mainly of ‎molluscs’ and therefore it can determine some environments prevailing in the lake. ‎Results indicated for examining configuration qualitative benthic macro during the study ‎period were recorded 27 species, including 9 species of living benthic macro organisms ‎include one type of aquatic submerged vascular plants of species Potamogeton ‎pectinatus. Although higher values of taxonomic richness, the Shannon and index (H`) ‎and evenness (J`) were obtained with the water Potamogeton pectinatus habitat as well ‎as Ostracoda Sclerochilus contortus were most abundant.‎

Megalaspis cordyla is one of the Carangid fish species commonly found in marine areas ‎of the Sundarbans and the Bay of Bengal in Bangladesh. This study described the ‎morphometric relationships including length-weight and length-length relations (LWRs ‎and LLRs) and meristic characteristics of M. cordyla. A total of 100 individuals were ‎collected from commercial fishers’ catch in the Bay of Bengal, Bangladesh during ‎January-December 2021. For each individual, a total of fourteen various lengths were ‎measured by measuring board with 0.01 cm and body weight (BW) was taken by digital ‎balance with 0.01 g accuracy. Fin-ray numbers from all fins as well as scutes were ‎counted by a magnifying glass. Total length (TL) varied from 17.0-36.5 cm and the total ‎body weight (BW) ranged from 75.0-416.6 g. All LWRs were significantly related (p < ‎‎0.001), with r2 values ≥ 0.910. Based on r2 value (0.979), LWR by BW vs. TL (W= a × Lb) ‎was the best fitted model among 14 equations. Besides, the LLRs were also significant ‎with r2 values ≥ 0.908. According to r2 value (0.995), LLR by TL vs. FL (TL = a + b× FL) ‎was the best fitted model among 14 equations. The fin formula of M. cordyla is: first ‎dorsal, D1 I+VII; second dorsal, D2 I/14-18+6-8 finlets; pectoral, P1 20-26; pelvic, P2 I/5; ‎anal, A II+I/12-16 +5-7 finlets. This study provided knowledge on morphometric and ‎meristic features that would be very useful for species identification and stock ‎assessment of M. cordyla in the Bay of Bengal and other marine ecosystems.‎

The box crab Calappa exanthematosa Alcock and Anderson, (1894) re-described ‎from the coastal waters of Pakistan. C. exanthematosa was collected as a bycatch during ‎the shrimp trawling. This species previously synonymised under C. japonica ‎Ortmann, (1892) from the Bay of Bengal, (type locality Japan), since 1937 to till date ‎‎(Galil, 1997; Spiridinov and Apel, 2007). Ng et al., (2011) re-described and illustrated the ‎C exanthematosa after comparison of freshly collected specimen of Calappa japonica ‎from the Gulf of Oman and India and revealed that the both species have resemblance ‎to each other, but few marked differences exist between both species. Current study re-‎described the morphological characteristic of C. exanthematosa from the coastal waters ‎of Pakistan.‎

A Sawback angel shark (Squatina aculeata) classified as “Critically Endangered” Global ‎Red List by the IUCN (2017) and CITES (2017) is one of the threated elasmobranch ‎groups and the increased pollution in the marine environment negatively impact angel ‎shark species. Despite this, limited information exists about the effects of toxic chemical ‎contamination in angel sharks. Therefore, present study was conducted to elucidate ‎heavy metal accumulation in Squatina aculeata captured from the Iskenderun Bay, ‎North-Eastern Mediterranean by electrochemical technique. Arsenic (As), Mercury (Hg), ‎Copper (Cu), Iron (Fe), Zinc (Zn) and Mangan (Mn) were found by electrochemical ‎analyzer. Among the gill and liver tissue samples of S. aculeata, Fe and Zn were detected ‎as highest concentrations followed by As, Hg, Mn and Cu; Among the muscle tissue of S. ‎aculeata, Fe and Zn were detected as highest followed by Hg, As, Mn and Cu. Average ‎total arsenic contents in S. aculeata was 7.5416±0.6548 μg g-1, which exceeded ‎maximum limit legalized for any kind of food. Similarly, Total mercury average content ‎in S. aculeata was 19.9942±1.6116 μg g -1, which exceeded the proposed limit value ‎which is 0.2-2 μg g-1, confirming that the consumption of S. aculeata is a high risk ‎threating the health of consumer. These results confirmed that the metal contamination ‎in North-Eastern Mediterranean area may pose a potential threat to the sustainability of ‎S. aculeata in marine ecosystem and the concentrations detected is the above the safety ‎limits for angel shark that should be taken into consideration regarding human ‎consumption.‎

Lake Manzalah one of the northern Nile Delta in Egypt is the largest lake, which lies ‎between the lakes Borollus and Bardaweel and connects to the Mediterranean Sea. It ‎has an area of current 250 thousand acres. It contains many islands particularly along ‎the south-western region forming of semi-enclosed basins and it is characterized by dense ‎submerged hydrophytes as Pomatogeton pectinals; Ceratophyllum demersum and ‎floating hyacinth Eichhornia crassipes. Seven major drains are loading directly in the ‎south to the west. Lake Manzalah-bottomed shallow (0.5-1m), brackish water (3-18‰ ‎and is suffering from the phenomenon of high nutrition (eutrophication) due to increased ‎rates of nutrients and organic matter. So some sources of wastes discharges such as ‎sewage and industrial waste and agricultural activity pour directly into the lake, ‎especially the southern region (Bahr El Baqar Drain). The study aims to study the ‎distribution of benthic organisms in the lake and knowledge of the relationship between ‎the types and aggregates benthic food ecosystem as the important food sources' for ‎some aquatic organisms, especially economic fish and crustaceans in study stations. ‎Bottom sediment samples were collected from 11 sites by grab sampler covering ‎different environments lake and from 4 drains consists mostly of organic materials ‎‎(sludge) is made up of waste sewage, industrial, agricultural waste plants, and calcareous ‎shells empty. Results indicate for examining configuration qualitative macro benthic ‎recording the 16 species of aquatic plants and invertebrates where empty calcareous ‎shells were more frequent. The abundance of macrobenthic organisms at different ‎sampling sites along Lake Manzala can be ranked as follows: Ostracoda (45.4%, 1010 ‎ind/m2) > submerged plants (12.9%, 287 tufts/m2) > Amphipoda (9.2%, 207 ind ∕m2) > ‎Polychaetes (7%, 110 ind ∕m2) Bivalves (5.9%, 132 ind ∕m2). The biomass of benthic ‎assemblages at different sampling sites can also be ranked as follows: at ST5 (18.1%, ‎‎4433 ind ∕m2) > St6 (11.3%, 2772 ind ∕m2) > ST8 (9.8%, 2405 ind ∕m2) > ST3 (9.2%, 2247) ‎‎> ST7 (8.7%, 2122 ind ∕m2). The biomass of benthic assemblages at different sampling ‎sites can also be ranked as follows: echinoderms (52%) > molluscs (27%) > crustaceans ‎‎(16%) > polychaetes (2%) > other groups (3%). Due to the increase of pollutants ‎extensively loaded into the drains are the possible factors having affecting the ‎constituents’ structures of benthos. Sites of sampling study were evenly spread (J’ > 0.8) ‎only at sites 6 and 8, moderate diversity (H’ > 1.00) was at most sites and show lower ‎value at sites 3 and 11 and 0 at site 1. The abiotic environmental effects in the lake are ‎general to those generally observed in other areas influenced by organic wastes, namely, ‎changes in the physic-chemical properties of the sediments and low oxygen ‎concentrations in the bottom water due to the decomposition of organic materials.‎

This study was conducted to estimate the prevalence, mean abundance, and mean ‎intensity of Haemogregarina infection on Sawrow fish (Trachurus mediterraneus) from ‎Zliten coast, Libya. A total of 12 specimens of Sawrow fish species were collected ‎randomly, the length (19.23 ± 0.72cm) and the weight (110.25 ± 7.88 g). The fish were ‎transported immediately alive to the laboratory in the Department of Fish Biology and ‎Fish Culture, College of Marine Resources, Asmarya University, where they were ‎maintained alive in well aerated glass aquaria (1x2x4 m). The gills, fins, and skin were ‎examined for ectoparasitic protozoa using a light microscope. The results showed ‎positive effect of haemogregarina in the Sawrow. Blood recorded the highest prevalence ‎and abundance among all the other organs in Sawrow fish followed by kideny, liver and ‎spleen respectively. The results provide a significant difference at (p<0.01), and the ‎results were discussed with other studies in the haemogregarinidae.‎