International Journal of Aquatic Biology
Volume:7 Issue: 4, Aug 2019

Marine biodiversity along the Syrian coast is affected by climate change-related temperature increase leading to the migration and entrance of alien species, especially from the Suez Canal (biological invasion). The Syrian coast is chracterized by many different types of habitats, including marine caves, midilittoral bioconstructions ( Lithophyllum byssoides rim and vermetid tarraces), coraligenous communities, sandy dunes, rocky coast and seagrass meadows. The present study summarizes early and most recent results on the presence, distribution, abundance and conservation status of marine alien species along the Syrian coast and provides an updated list of alien macrozoobenthic species. A total of 79 alien species belonging to Mollusca, Crustacea, Tunicata, Polychaeta, Spongia, Echinodermata and Chaetognatha are reported; among them Gastropoda is being the most abundant and successful taxon. In the light of these results, some recommendations on future research directions are provided. In particular, more effort is needed to monitor and record the entrance of alien species by adopting a comprehensive national plan to study marine biodiversity and to protect local resources in the Syrian marine environment.

: The effects of 21 days exposure to lufenuron and flonicamid were investigated on common carp responses to saltwater exposure. Fish were assigned in three groups: control (21 days in freshwater), lufenuron (exposed for 21 days) and flonicamid (exposed for 21 days). After 21 days, all fish were subjected to 15 g/l saltwater for further 4 days. Plasma glucose, cortisol, sodium, potassium, chloride, calcium and phosphorus levels were monitored 0, 24, 72 and 120 h after saltwater exposure. Type of pesticides and time of salt water exposure had interaction on plasma glucose and cortisol levels. These two stress indicators were increased significantly in all groups after saltwater exposure. The cortisol elevation continued until 72 h after salinity challenge and then decreased significantly after 120 h salinity exposure in all treatments. Plasma glucose level showed fluctuation during saltwater exposure. It was increased after 24 h saltwater exposure, then decreased after 72 h and again it was increased after 120 h salinity challenge. Increased plasma sodium showed significant elevation along with elongation of saltwater exposure. Pesticide exposure significantly affected plasma chloride levels as the flonicamid group had significantly lower chloride compared to the control and lufenuron groups. Plasma chloride showed significant elevation along with elongation of saltwater exposure. Pesticide and time of salinity challenge had interaction on plasma calcium levels as 24 h after salinity challenge calcium level of pesticide groups increased significantly. Along with elongation of saltwater exposure, calcium level of pesticides treatments decreased but it higher than the pre salinity challenge. Plasma phosphorus level increased 24 h after saltwater exposure and decreased along with elongation of saltwater exposure. In conclusion, lufenuron and flonicamid induce stress and alter gill function and blood ionic homeostasis during saltwater exposure.

Poecilia sphnop  and P . reticulata are considered as two most popular and high demanding freshwater ornamental fish species globally. The effects of feeding frequency, feed protein level, photoperiod and salinity on growth and survival of these species and the effect of sex ratio on fecundity were studied under laboratory conditions from January to December 2016. Although there was no any significant impact of feeding frequency on growth and survival of these species, feed protein content affected significantly on their growth. Fry fed with newly hatched Artemia, commercial larval feeds and Chlorella sp. showed no significant impact on growth. Poecilia sphenops and P. reticulata could tolerate salinity up to 10 and 25 ppt, respectively. Fish exposed to 8 hrs photoperiod reported significantly lower growth than those who were exposed to 12 and 24 hrs photoperiods. The ideal female: male sex ratio for commercial stocking of P . sphenops and P. reticulata was 3:2.

Florfenicol (FF) is a common, inexpensive antibiotic with relatively low toxicity. The present study investigates the possible effects of Florfenicol on cutaneous mucus immune parameters and immune related genes expression in Danio rerio . After two weeks adaptation, fish were stocked in experimental units at density of 20 fish per aquaria and fed with experimental diets containing 0, 10, 30 and 50 mg/kg FF per for 11 days. Evaluation of immune parameters at the end of trial showed that the control group had a significantly lower level of lysozyme activity when compared with those treated with antibiotic. However, the skin mucus total immunoglobulins level of fish fed diets containing antibiotics did not show any significant difference compared to the control group. The highest expression level of TNF-α, IL1β and lysozyme was observed in fish treated with 10 mg/kg FF while the lowest expression was noticed in those fish treated with 30 and 50 mg/kg FF. The present results indicate the relatively positive effects of this antibiotic on the immune system of zebrafish, and it seems that the appropriate dosage of the drug can serve as an immunostimulant for zebrafish.

This work presents some biological properties, including length-frequency, length-weight relationships, Fulton’s condition factor, growth parameter, and growth performance and mortality indices of Kura goby, Ponticola cyrius . A total of 73 specimens were collected from the Çot Creek a tributary of Kura River, from May to September 2015. Age of P. cyrius varied from 0 to III age with age group I as the most frequent (56.16%). The total length and weight ranged 4.3-16.4 cm, and 1.1050.10 g, respectively. The length-weight relationship was W =0.0145 L 2.9795 with b -value indicating isometric growth pattern . The estimated von Bertalanffy growth parameters are L  = 26.36 cm, k = 0.187 year-1 and t o = -1.33 year. Growth performance index (Φ') and mean Fulton’s condition factor were estimated as 2.115 and 1.43, respectively. Instantaneous rate of total, natural and fishing mortalities were 0.588, 0.371 and 0.217 year-1, respectively and the exploitation rate was calculated as 0.369.

Lactococcus garvieae is known as main agent of the bacterial diseases, Lactococcosis in trout farms. The present study was aimed to study the metabolic bases of the temperature-dependent pathogenicity of the L . garvieae using 1H NMR spectroscopy. The bacteria were grown at different temperatures, including 10, 14, 18 and 22˚C and then the metabolites extracted, identified and quantified. The results of PLS-DA analysis clearly separated the experimental treatments. The main metabolites responsible for this separation were acetate, acetoacetate, creatine phosphate, succinylacetone and trehalose. Furthermore, the result of the analysis of variance indicated also significant differences in metabolome content between temperature treatments. The bacteria exposed to higher temperatures showed more concentration of acetate and acetoacetate compared to those grown at 10°C. The concentrations of trehalose were higher in the bacteria grown at 14 and 18°C compared to other temperature treatments. The higher levels of succinylacetone were found in the bacteria exposed to the temperature less than 14°C compared to those grown at 18 and 22°C. The creatine phosphate concentrations increased with temperature, however, a significant decline occurred at 22°C. The levels of isoeugenol, methionine and betaine significantly declined with increase of temperature from 10 to 22°C. Also, the concentration of N-Acetylglutamine significantly raised as the temperature increased from 10 to 22°C. In conclusion, the temperature altered the metabolome of L. garvie , which this may be linked to the pathogenicity. The temperature probably affects fermentation, homeostasis, energetic condition and metabolism of amino acids in L. garvieae .

: Growth performance, survival, and feed efficiency in native catfish, Clarias microcephalus, fed chicken entrails, earthworm meal, and low-value fish meal were investigated. A simple cost-benefit analysis using this fattening approach was done to evaluate the profitability of using these low-value feed ingredients. Nine 30L aquaria were stocked with native catfish juveniles (about 20 cm in total length and 80 g in weight) at a density of 1 fish per liter. The catfish were fed cooked chicken entrails (Treatment 1), earthworm meal (Treatment 2) and low-value fish meal (Treatment 3) at 3% body weight for 60 days. At the end of the feeding trial, the growth of the fish fed various low-cost feeds was not significantly different. Survival was better in fish fed cooked chicken entrails than with either earthworm meal or low-value fish meal. Feed conversion efficiency (FCE) was relatively similar among the three types of feeds. A simple cost-benefit analysis using these low-cost feeds showed a return of investment (ROI) of 68-79%, indicating the feasibility of using these feeds for fattening of catfish. These preliminary results show that utilizing low value feed ingredients or food wastes as sources of feeds during fattening of native catfish are feasible. In addition, food wastage is reduced by bringing these food sources back to the food chain during aquaculture operations.

Barbus urmianus from the Mahabad-Chai River in Urmia Lake basin, is distinguished from its congeners in the B. lacerta group by a well-developed middle pad of the lower lip, a shorter postdorsal length (25.2–42.0 vs. 46.4–60.7% SL), long anal fin (11.0–23.0 vs. 6.0–10.4% SL), short dorsal-fin base (9.2–15.6 vs. 16.1–22.6% SL), less scales in the caudal peduncle (14–23 vs. 25–35), and 64–85 scales on the lateral line (vs. 52–70).