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Öğe A review on heavy metal levels in sea cucumbers(2020) Bat, Levent; Ahmed, Quratulan; Öztekin, Ayşah; Arıcı, ElifHeavy metals can remain in the marine ecosystems for a long time, they may affect biota in the food chain as a result. Sometimes theexistence of xenobiotics causes so great a alter in the ecosystem that a return to earlier, natural conditions is not viable. Human pressureon the sea’s resources is increasing, it affects the health of many organisms, leading to changes in the food chains and influencingaccumulation in the tissues of biota. Sea cucumbers are being used for heavy metal pollution studies. They are preferred with theirmany features such as easy collection from the land, feeding with organic matter, contact with sediment, maintenance in laboratories,obtaining sufficient tissue, consuming some species. This review covers heavy metal studies with sea cucumbers in different seas. Theresults are compared with each other. In addition, the evaluation of the consumed sea cucumber species in terms of human health hasbeen discussed.Öğe A Review on Studies of Heavy Metal Determination in Mackerel and Tuna (Family-Scombridae) Fishes(Bülent VEREP, 2018) Ahmed, Quratulan; Bat, Levent; Öztekin, Aysah; Ali, Qadeer MohammadIn this review, the chemicals, some of the mostimportant of which are heavy metals and their accumulation level in Mackerels,Tunas, and Bonitos in mainly the Arabian Sea and coastland in other seas werereviewed and compared.Öğe A Review on Studies of Heavy Metal Determination in Mackerel and Tuna (FamilyScombridae) Fishes(2018) Ahmed, Quratulan; Bat, Levent; Öztekin, Aysah; Ali, Qadeer MohammadMany chemicals especially heavy metals that are exist in fish are essential for human life at low amounts, but can be toxicat high amounts. Other chemicals such as Hg, As, Cd and Pb have not any essential function in biota and are toxic even at very low amountswhen ingested for a long period. The aim of this review is to compare and evaluate heavy metal levels in commercial fish species from theArabian Sea and coastline in other seas. In this review, Mackerels, Tunas and Bonitos species, the most commercial of Scombridae family, werechosen. The state of the metal pollution levels of these fishes is revealed under the light of the literature. The chemicals, some of which are themost important heavy metals such as Zn, Fe, Cu, Pb, Cd, Hg, As, Cr and Mn were chosen and their amounts in commercial fish were evaluated.Most of studies showed that essential metals in fish species are much high, but the quantities of non-essential metals in edible tissues offish are found to be less. This review has shown that fish are used as bio-monitoring in heavy metal pollution. It is suggested that suchinvestigations should be continuous in terms of both human health and determination of metal pollution of our coasts.Öğe A Study on Diet Composition and Feeding Habits of Sphyraena putnamae Jordan & Seale, 1905 from the Northern Arabian Sea(Central Fisheries Research Inst, 2025) Zohra, Kashifa; Yousuf, Farzana; Ahmed, Quratulan; Ali, Qadeer Mohammad; Bilgin, Sabri; Bat, LeventThe food and feeding habits of the Sphyraena putnamae (n=381) ranging from 16 to 99 cm were investigated the Karachi coast, the Northern Arabian Sea, Pakistan. S. putnamae consumed various prey items, which were divided into three categories: teleosts, molluscs, and crustaceans. Molluscs and crustaceans were the second preferred food component rather than teleost. The major constituents of the teleost group on basis of their ascendancy, were identified to be (dorosomatids; sciaenids; leiognathids; platycephalids; engraulids; carangids; bregmacerotids; nemipterids; scombrids; and synodontids). The empty stomach ratio and stomach fullness index did not differ significantly between the sexes and size classes. The stomach fullness index of juvenile barracudas (16-29 cm in length) was significantly higher as compared to adults in the medium (30-55 cm) and large (56-99 cm) size groups. Additionally, an analysis of dietary preferences revealed that small (juvenile) barracudas (16-29 cm) primarily consumed crustaceans, while medium-sized individuals (30-55 cm) preferred mollusks, and large individuals (56-99 cm) favoured teleost. The present study provides detailed information on the feeding ecology of the S. putnamae, for the first time from the Pakistan coast that will be useful for understanding trophodynamics of species developing effective management and conservation measures, ensuring the species' long-term viability.Öğe ANALYSIS OF MERCURY (HG) IN FOUR HOLOTHURIANS SPECIES (PHYLUM-ECHINODERMATA) FROM KARACHI COAST-NORTHERN ARABIAN SEA(2018) Ahmed, Quratulan; Bat, Levent; Alı, Qadeer MohammadNowadays metal bioaccumulation in holothuroids is increasing and is a cause of worry owing totoxicity. In the present study the concentrations of mercury (Hg) were measured in holothuroids(Holothuria (Thymiosycia) arenicola Semper, 1868, Holothuria (Lessonothuria) pardalis Selenka,1867, Holothuria (Lessonothuria) verrucosa Selenka, 1867 and Holothuria (Halodeima) atraJaeger, 1833) collected during different seasons (pre-monsoon, monsoon, and post-monsoon) in2015 at Buleji and Sunehri coasts of Karachi, Pakistan. Hg concentrations of tentacles were higherthan those in muscle, tentacle and gut tissues of the pre-monsoon, monsoon and post-monsoon.The lowest Hg concentrations were found in muscle tissues at all seasons in Buleji and Sunehricoasts. The mean levels in the muscle tissues were 0.018 mg/kg dry wt. for H. arenicola, 0.024mg/kg dry wt. for H. verrucosa, 0.026 mg/kg dry wt. for H. pardalis and 0.036 mg/kg dry wt. forH. Atra. The results indicate that according to the European Union legislation the Hg amounts inall tissues of holothurians is much lower than permitted levels. In terms of Estimated WeeklyIntakes, this current work also proved that there was no likely health hazard to consumers on account of intake of sea cucumbers under the current consumption rate in Buleji and Sunehri coastsof Karachi, Arabian Sea.Öğe Analysis of Microplastic in Holothuria leucospilota (Echinodermata-Holothuroidea) and Sediments from Karachi coast, (Northern Arabian Sea)(2023) Ahmed, Quratulan; Öztekin, Ayşah; Alı, Qadeer Mohammad; Bat, Levent; Shaikh, IqraMicroplastics are found in all aquatic environments, and they can have several negative impacts on marine life. In this study, the distribution of microplastics in the sediment and in the organs (gut, respiratory tree, and tentacles) of sea cucumber (Holothuria leucospilota) collected from Mubarak Village and Cape Monze on the Karachi coast of Pakistan were investigated. The microplastic amount in different organs of H. leucospilota was found as 15.3-40.45 pieces/individual in the gut, 15.45-23.9 pieces/individual in the respiratory tree, 8.9-9.55 pieces/individual in tentacles. The microplastic amount of sediment samples was 57.40-129.35 pieces/kg. Fibers were the dominant microplastic type, up to 99% of all samples. The results of the present study show that the region is contaminated with microplastics both in biota and in sediments.Öğe Assessment of Hg in Holothuria (Mertensiothuria) leucospilota (Brandt, 1835) from Karachi coasts, Pakistan(Kahramanmaras Sutcu Imam Univ Rektorlugu, 2020) Ahmed, Quratulan; Bat, LeventThe aim of the present study was to determine mercury levels in sediments, surface sea water and Holothuria leucospilota muscles and skin in two selected sites from Karachi coast. Samples were collected during two seasons south-west monsoon (August-September) and north-east monsoon (December-January). The concentrations of Hg in sediment ranged from 0.0012 to 0.0023 mg kg(-1), and in surface water from 0.00018 to 0.00034 (mu g l(-1)), while in muscle and skin of black sea cucumber ranged from LOD to 0.0034 and LOD to 0.0046 mg kg(-1) dry wt., respectively. Moreover, Hg showed the highest accumulation rate in the skin tissue with BSAF values ranging between 2 in Buleji and 2.69 in Sunehri at north-east monsoon. The BSAF values in the muscles of the black sea cucumber ranged from 1.44 at south-west monsoon in Buleji to 1.63 at north-east monsoon in Sunehri, respectively. Since BSAF value is higher than 2 on the skin of sea cucumber, it is evaluated as macro-concentrator. However, the BSAF value varies between 1 and 2 in muscle, it has been determined as micro-concentrator. Hg in the black sea cucumbers from Buleji and Sunehri sites of the Karachi coasts is very bio-accumulative (BCF > 5000) during both sampling seasons.Öğe Comparison of electronic length frequency analysis (ELEFAN) for estimation of growth parameters for lollyfish, Holothuria (Holothuria) atra and sand sea cucumber, Holothuria (Thymiosycia) arenicola (Holothuroidea: Echinodermata) in the north Arabian Sea, Pakistan(2020) Ahmed, Quratulan; Bilgin, Sabri; Alı, Qadeer MohammadTo estimate the growth parameters, the non-seasonal von Bertalanffy and Hoenig seasonal von Bertalanffy models were fitted to the length frequency data of Holothuria atra and H. arenicola obtained from coastal areas of Karachi in the northern Arabian Sea, Pakistan between January and December 2014. The Hoenig seasonal von Bertalanffy growth parameters were estimated as L∞=36.1 cm total length (TL), K=0.75 year-1 for H. atra and as L∞=34.9 cm TL, K=0.70 year-1 for H. arenicola. H. atra individuals reached 73.9% of their maximum total length at the one year old. For H. arenicola it was calculated as 72.7%. Monthly mean growth rate of H. atra at the same ages was calculated higher than H. arenicola. The seasonal oscillation in growth rate for H. atra (C=0.50) was larger than it was for H. arenicola (C=0.37). The time of the year when the growth is slowest corresponded to the middle of April (WP=0.30) in H. atra and at the beginning of August (WP=0.60) in H. arenicola may be the result of the extended both reproduction and poor nutrition periods due to monsoonal effects on the marine environment. The relatively high growth rates (K>0.7 year-1) of these two species may have important implications for high survival rate, particularly in environmental condition where cause biological stress and marine confusion but may also increase their potential as a candidate species for aquaculture.Öğe Heavy Metals in Terapon puta (Cuvier, 1829) from Karachi Coasts, Pakistan(Hindawi Publishing Corporation, 2015) Ahmed, Quratulan; Bat, Levent; Yousuf, FarzanaThis study was carried out to investigate the accumulation of Fe, Mn, Cd, Pb, and Ni in Terapon puta from Karachi Fish Harbor, Pakistan. There were no significant differences in the concentration of the metals except Mn in T. puta, which is obtained from the different seasons. The highest metal concentration is Fe followed by Mn. Cd, Pb, and Ni were measured relatively lower concentrations. The mean (± SD) Fe, Mn, Cd, Ni, and Pb levels in the muscles tissues of T. puta were 25.5±13.71, 6.07±3.58, 0.47±0.29, 0.46±0.27, and 0.43±0.25 mg/kg dry wt., respectively, whereas the mean (± SD) Fe, Mn, Cd, Ni, and Pb levels in the liver tissues of T. puta were 562±105, 18.62±11.86, 1.06±0.47, 1.20±0.53, and 1.01±0.50 mg/kg dry wt., respectively. Cd and Pb levels exceeded the Commission Regulation of European Union maximum limit of 0.05 mg/kg and 0.30 mg/kg, respectively. However, the results of Estimated Weekly Intake and Estimated Daily Intake indicate that the heavy metal levels in the samples are generally within respective recommended guidelines. Thus, it would appear from this study that the heavy metal levels in T. puta from Karachi coasts are low enough not to present a health hazard if the fish are consumed, although due attention should be paid to the maximum acceptable daily intake per kilogram body weight. © 2015 Quratulan Ahmed et al.Öğe Length Based Growth Estimation of Most Commercially Important Scombridae from Offshore Water of Pakistan Coast in the Arabian Sea(2016) Ahmed, Quratulan; Bilgin, Sabri; Bat, LeventSeasonal growth pattern of skipjack tuna (Katsuwonus pelamis), longtail tuna (Thunnus tonggol), kawakawa (Euthynnus affinis) and king mackerel (Scomberomorus guttatus) were studied during five years period (between August 2006 and December 2011). Seasonal samplings of the species were collected from offshore water of Pakistan coast in the Arabian Sea. The weight - length relationships (WLRs) among the species except E. affinis demonstrated that the growth is allometric type (Pauly's t test, P < 0.005). The seasonal von Bertalanffy growth model parameters computed from seasonal length - frequency distributions, were estimated as L? 67.1 cm TL, K 1.055 year, C 0.990 for E. affinis, as L? 66.8 cm TL, K 1.378 year and C 0.950 for K. pelamis, as L? 71.7 cm TL, K 0.916 year and C 0.849 for T. tonggol, as L? 55.7 cm TL, K 1.049 year and C 0.980 for S. guttatus. The seasonal oscillation in growth rate was determined for the species (C > 0.8). The slowest period of growth corresponded to in September (WP 0.7) for E. affinis, (WP 0.6) in August for K. pelamis, (WP 0.4) in May for T. tonggol and (WP 0.0) in January for S. guttatus.Öğe Length Based Growth Estimation of Sea Cucumbers (Holothuria verrucosa and Holothuria pardalis) (Holothuroidea:Echinodermata) Collected from Coastal Areas of Karachi, Pakistan (northern Arabian Sea)(2020) Ahmed, Quratulan; Bilgin, Sabri; Alı, Qadeer MohammadNon-seasonal von Bertalanffy and Hoenig seasonal von Bertalanffy models were fittedto the length frequency data of Holothuria pardalis and Holothuria verucosa sampled from thecoastal areas of Karachi between January and December 2018 for estimating the growthparameters. The Hoenig seasonal von Bertalanffy growth parameters were estimated as L∞ = 18.0cm total length (TL), K = 1. 00 year-1for H. pardalis and as L∞ = 18.0 cm TL, K = 0.86 year-1forH. verrucosa. H. verrucosa individuals reached 68.9% of their maximum total length at the oneyear old age class. For H. pardalis it was calculated as 54.2%. The seasonal oscillation in growthrate for H. pardalis (C = 0.90) was larger than it was for H. verrucosa (C = 0.18). The slowestperiod of growth corresponded to June in H. verrucosa and February in H. pardalis may be theresult of the extended both reproduction and poor nutrition periods due to high rainfall regime.The relatively high calculated values of growth rate parameters for both species may have animportant state for their survival rate under the condition of biological stress, but may alsoincrease their potential as a candidate species for aquaculture.Öğe Metals levels in Sarda orientalis collected from the commercial landings of Karachi Fish Harbor, Pakistan (northern Arabian Sea) and assessment of likely health risks to the consumers(Taylor & Francis Inc, 2023) Ahmed, Quratulan; Bat, Levent; Oztekin, Aysah; Ali, Qadeer Mohammad; Ghory, Farhana Shafiq; Yousuf, FarzanaAnthropogenic activities are the major source of chemical pollutants including heavy metals in the coastal ecosystem which may accumulate in the aquatic organisms through the food web. Metal contamination in the marine fish pose serious threat to human health. This study deals with the human health risks of metal accumulation from Sarda orientalis consumption. The quantities of heavy metals were investigated in muscle, gills, and liver of striped bonito from the commercial landings of Karachi Fish Harbor, Pakistan (northern Arabian Sea). Risk for human health was evaluated by iron, zinc, manganese, copper, lead, cadmium, estimated daily intake, hazard index, and risk index. The hazard index value is <1, indicating that the estimated exposure is below reference dose for the relevant metals for monsoon, winter, and pre-monsoon. The mean hazard index for iron, zinc, manganese, copper, lead, and cadmium was 1.20 x 10(-2) for consumers. The mean risk index of lead for S. orientalis was 7.39 x 10(-9). As a result, the metals did not exceed the World Health Organization's and the United States Environmental Protection Agency's toxicological reference.Öğe Morphological Description of Megalopal Stages of Three Portunid Species (Decapoda, Brachyura, Portunidae) from Indus Deltaic Area (northern-Arabian Sea)(Natural and Engineering Science, 2023) Inam, Urwah; Ali, Qadeer Mohammad; Ahmed, Quratulan; Bat, LeventThe larvae of crustaceans, including those of brachyuran crabs, are a significant part of zooplanktonic communities constituting an ecologically important fraction of the pelagic communities. The present study describes taxonomic studies on three megalop stages of Portunus pelagicus (Linnaeus, 1758), Charybdis feriatus (Linnaeus, 1758) and Carcinus maenas (Linnaeus, 1758) belonging to family Portunidae collected from Indus deltaic creek system. Zooplankton samples were collected from three locations: Shahbandar 24°15’48.083’N, 67°90’15’333’E, Ketibandar 24°9’16.06’N, 67°27’7.64’E and Korangi creek 24°48’18.80’’N, 67°12’30.31’E during April to October 2018. No data available on taxonomic studies of portunid megalops upto species level from Paksitan, hence this is a first attempt to examine and to describe taxonomic features of megalops collected in the zooplankton samples. This study will contribute to the scientific knowledge on megalops taxonomy and identification as well as be useful for future research by taxonomists and biologists. © 2023, Natural and Engineering Science. All rights reserved.Öğe Preliminary Observation on Microplastic Contamination in the Scombridae Species From Coastal Waters of Pakistan(2022) Yousuf, Farzana; Bat, Levent; Öztekin, Ayşah; Alı, Qadeer Mohammad; Ahmed, Quratulan; Shaikh, IqraMicroplastics are one of the major pollution problems nowadays, have been found in both marine environments and various fish species worldwide. In this study, the presence of microplastics in the digestive systems and the gills of 6 species from the Scombridae family on the coast of Karachi in Pakistan was investigated. A total of 336 fish were examined for the presence of microplastic in gills and the digestive systems. Microplastics were detected in digestive systems and gills in 11.11%-19.51% and 58.62%-85.71% of total individuals, respectively. The number of microplastics varied from 0.19 to 1.12 items.ind-1 in digestive system and 1.5 to 7.04 items.ind-1 in gill. Fibre was dominant in both gills (98.67-99.17%) and digestive systems (100%). More extensive and further investigations are needed on microplastic contamination of the biota on the Pakistan coast.Öğe Preliminary Study on Abundance of Microplastic in Sediments and Water Samples Along the Coast of Pakistan (Sindh and Balochistan)-Northern Arabian Sea(Central Fisheries Research Inst, 2022) Ahmed, Quratulan; Ali, Qadeer Mohammad; Bat, Levent; Oztekin, Aysah; Memon, Sehrish; Baloch, AzizullahPlastic material dominates our life and accordingly, it dominates the environment as a pollutant. Pakistan coasts are facing with plastic pollution problem like the rest of the world. The number and types of microplastics found in sea water and sediment samples from 25 locations along the Arabian Sea coast of Pakistan were explored in this study. The results of the present study show that the region is under a high pollution from microplastics. Microplastic abundance in seawater was found as mean 582.12 +/- 246.14 particle. L-1 and in sediment samples was mean 987.40 +/- 617.06 particle.kg-1 dry sediment. Microplastic concentration was maximum in Manora both seawater and sediment samples. Fibers were major contribution to total microplastics, up to 99% of all samples both seawater and sediment samples.Öğe Seasonal Abundance of Fish Larvae in Shahbandar Creek, Indus Deltaic Area, Sindh(Springer Int Publ Ag, 2025) Ali, Qadeer Mohammad; Ahmed, Quratulan; Elahi, Naeema; Mavruk, Sinan; Bat, LeventThe availability of near-shore vegetated environments, such as seagrass meadows and mangroves, plays a crucial role in maintaining the sustainability of fish stocks. The present study investigates the seasonal changes of abundance of fish larvae in Shahbandar Creek, Indus Delta region, Sindh from April 2018 to January 2019. Physico-chemical characteristics of sea water were measured, including air and water temperature (degrees C); salinity (ppt), dissolved oxygen (mg/L); pH and transparency (cm). The highest seasonal larval abundance values were observed in inter-monsoon period (October) through 500 mu m (39 ind./100m3) and 250 mu m (62 ind./100m3) mesh size. The most abundant families were Clupeidae (24%), Carangidae (13%), Gobiidae (19%), Sciaenidae (12%), Engraulidae (15%) and Syngnathidae (17%) during the study period.Öğe Seasonal effects on length-weight relationship and condition factor of Holothuria pardalis (Holothuroidea: Echinodermata) collected from Karachi coast-Northern Arabian sea(Cahiers De Biologie Marine, 2019) Ahmed, Quratulan; Bilgin, Sabri; Ali, Qadeer MohammadThis study was conducted to determine the effects of seasonal variation on condition factor (CF) and weight length relationships (WLRs) in Holothuria pardalis collected during January to December 2016. Total (n = 452) sample of H. pardalis were collected during pre monsoon, monsoon and post monsoon season from two rocky shores of Buleji and Sunehri coast of Karachi. The highest mean length 17.1 +/- 0.70 cm and weight 20.3 +/- 0.63 g were recorded in post-monsoon season and minimum length 10.7 +/- 0.59 cm and weight 14.0 +/- 0.72 g were recorded in pre-monsoon season. The results showed that H. pardalis has negative allometric (b < 3) growth characteristics in all seasons (P < 0.05) as it appears to be the general case in other holothurian species. One-way ANOVA test showed that the CF values were statistically difference among three seasons. The mean CF values in Buleji area were estimated statistically higher than in Sunehri in pre-monsoon and monsoon (P < 0.05). But, it was estimated lower in Buleji area than Sunehri area in post-monsoon (P < 0.05).Öğe Two New Records of Eunicidae (Annelida, Errantia) Along the Makran Coast of Pakistan, Northern Arabian Sea(Natural and Engineering Science, 2023) Ali, Qadeer Mohammad; Ahmed, Quratulan; Mubarak, Shumaila; Baloch, Ateeqa; Bat, Levent; Qazi, Hafsa; Shaikh, IqraThe Makran coast of Pakistan in the Northern Arabian Sea is a region of high biodiversity yet remains relatively under-studied in terms of polychaete fauna. In this study, we presented detailed morphological and taxonomical analyses of two newly discovered species of Eunicidae polychaetes, Eunice indica and Lysidice ninetta, collected during low tide from the intertidal zone of two stations along the Makran coast: Shamal Bandar, Pasni dated 31st January 2022 and Taak Beach, Ormara, dated 31st January 2022. Before our study, only 12 species of Eunicidae were known to occur in Pakistan. The identification and description of E. indica and L. ninetta provide important information about the distribution and taxonomy of Eunicid polychaetes on the Makran coast. These findings emphasize the need for further investigations and highlight the potential for discovering additional species within the region. © 2023, Natural and Engineering Science. All rights reserved.Öğe Two New Records of Polychaetes (Annelida) from Makran Coast of Balochistan, Pakistan (Northern Arabian Sea)(2024) Alı, Qadeer Mohammad; Ahmed, Quratulan; Baloch, Ateeqa; Mubarak, Shumaila; Qazi, Hafsa; Shaikh, Iqra; Kurt, GüleyThe Makran coast of Balochistan (Pakistan) is rich in terms of biodiversity particularly marine invertebrates. The study based on comprehensive assessment of the morphological and taxonomical description of two polychaete species (Eunice petersi Fauchald, 1992 and Hesione intertexta Grube, 1878). The newly recorded polychaete species for the coast of Pakistan belong to the Eunicidae and Hesionidae families and were identified in benthic samples collected from the intertidal zone on Garyan and Bandari beaches at Jiwani of the Makran coast (Northern Arabian Sea). The descriptions, photographs, and drawings of the taxonomic characters of species and their distribution are provided. The specimens are deposited in the repository of the Marine Reference Collection and Resource Centre, University of Karachi.
