Heavy Metal Concentration in Largehead Hairtail (Trichiurus lepturus Linneaus, 1758) and Savalai Hairtail (Lepturacanthus savala (Cuvier, 1829)) Obtained from Karachi Fish Harbour, Pakistan.

In this study, muscle samples gathered from Largehead hairtail (Trichiurus lepturus Linneaus, 1758) and Savali hairtail [Lepturacanthus savala (Cuvier, 1829)] from the Karachi Fish Harbour, Pakistan were analyzed to determine heavy metal concentrations (iron [Fe], zinc [Zn], copper [Cu], manganese [Mn], lead [Pb] and cadmium [Cd]) between January and December 2016. All samples were analyzed using the AAnalyst 700 Flame Atomic Absorption Spectrophotometer. It was observed that the average measured level of Fe, Zn, Cu, Mn, Pb and Cd in muscle were 77.72 ± 47.84 µg/g, 20.34 ± 8.49 µg/g, 2.23 ± 1.16 µg/g, 0.57 ± 0.36 µg/g, 0.20 ± 0.16 µg/g and 0.42 ± 0.19 µg/g for T. lepturus, respectively. Besides, the average level of the same metal concentrations in muscle for L. savala were 85.11 ± 57.64 µg/g, 16.63 ± 9.25 µg/g, 2.53 ± 1.90 µg/g, 0.47 ± 0.27 µg/g, 0.23 ± 0.18 µg/g and 0.47 ± 0.20 µg/g, respectively. The correlation between size groups and metal accumulation in muscle tissues were investigated for both fish. In terms of public risk assessment, the provisional tolerable weekly intake's of various heavy metals were compared with the consumption of both fish. As a result of the analysis, Fe, Zn, Cu, Mn, Pb and Cd accumulations in muscle tissues of T. lepturus and L. savala collected from Karachi Fish Harbour Pakistan did not exceed limit values.

Concentrations of Heavy Metals in Sardinella gibbosa (Bleeker, 1849) from the Coast of Balochistan, Pakistan.

The concentrations of cadmium, iron, lead, manganese, nickel, and zinc in muscle tissue samples taken from Goldstripe sardinella (Sardinella gibbosa Bleeker, 1849) caught off the coast of Balochistan, Pakistan, in 2009 were determined. The samples were analyzed using a Perkin Elmer AAnalyst 700 flame atomic absorption spectrophotometer. The mean Cd, Fe, Mn, Ni, Pb, and Zn concentrations in the muscle samples were 0.65±0.05 µg g(-1), 23.39±1.97 µg g(-1), 4.35±0.22 µg g(-1), 0.61±0.07 µg g(-1), 0.39±0.04 µg g(-1), and 6.59±0.33 µg g(-1), respectively. The Cd, Fe, Pb, and Zn concentrations did not exceed the regulatory limits, but the Mn concentrations were high enough to potentially pose health risks to humans consuming S. gibbosa. Therefore, the Mn concentrations in S. gibbosa from the Balochistan coast should be monitored regularly.

Afrocucumis africana (Semper, 1867) (Holothuroidea: Dendrochirotida:Cladolabidae), new addition to the holothuroid fauna of Pakistan.

Two dendrochirotid holothuroids, here identified as Afrocucumis africana, were collected from Gariyan Beach, Jiwani Makran Coast, Balochistan, for morphological and taxonomic study. This species is a new record of a dendrochirotid holothuroid from the Pakistani coastal waters. Identification was confirmed through morphology and microscopic observations of the ossicles. Identified specimens are deposited in Marine Reference Collection and Resource Centre, University of Karachi.

Effect of feeding frequency as a rearing system on biological performance, survival, body chemical composition and economic efficiency of Asian seabass Lates calcarifer (Bloch, 1790) reared under controlled environmental conditions.

A 70-day rearing trial was done to determine the optimal frequency of feeding on growth performance (GP), feed conversion rate (FCR), cannibalism, survival rate (SR), body chemical composition and economic efficiency of the Asian sea bass. This study tested four different treatments of feeding frequencies (FF), once (T1), twice (T2), three times (T3), and four times (T4) per day. An average initial weight of Asian sea bass fry was 0.2 g (SD = ±0.12) were stocked 10 individuals per m3 (9.14 m × 1.82 m × 1.22 m, L × W × H; water depth 0.61 m) with two replicates per treatment (4 × 2 = 8). Fry were fed a mixture of larval commercial feed and shrimp with a pellet diet containing (46% CP). Initially, the feeding rate of 8% biomass per day was further adjusted according to fish biomass on a weekly basis. Results showed that, the FF significantly affected (p < 0.05) on growth indictors and survival rate (SR). Specifically fry fed three times a day (T3) had the best FBW, FL, SGR, ADWG and FCR followed by T4 and T2 while fry fed one time a day was the lowest in these parameters. Also, VSI, HSI and CF (k) significantly differed among the treatments. The fish whole body content of protein, moisture and ash did not significantly (p < 0.05) be affected by feeding frequency, but lipid content differed and both T3, T4 were the highest. It could be concluded that, increasing FF up to three times a day had a positive effect on weight gain, survival rate and feed utilization of Lates calcarifer. The second degree polynomial regression indicates that fed three times a day is optimum for best growth performance and survival for Asian sea bass.

Holothuria (Lessonothuria) insignis Ludwig, 1875 (formally resurrected from synonymy of H. pardalis Selenka, 1867) and Holothuria (Lessonothuria) lineata Ludwig, 1875-new additions to the sea cucumber fauna of Pakistan, with a key to the subgenus Lessonothuria Deichmann (Echinodermata: Holothuroidea).

Two specimens of a species herein identified as Holothuria (Lessonothuria) insignis Ludwig, 1875 and a single specimen identified as Holothuria (Lessonothuria) lineata Ludwig, 1875, were collected from the intertidal zone at low tide from two coastal localities in Karachi (Buleji and Sunahri). This paper briefly documents their morphology and habitat characteristics and formally resurrects H. (L.) insignis from the synonymy of H. (L.) pardalis Selenka, 1867, based on the observations of the ossicles assemblage deduced from current material, syntype, some material at the NHMUK (Natural History Museum,UK), and literature. H. pardalis is also commented on and compared with its related congeners in Pakistan, in tabular form. A key is presented of all species of the Lessonothuria group currently recognized in WoRMS.