Diversity and Distribution of Fiddler Crabs (Crustacea: Brachyura: Ocypodidae) around the Arabian Sea.

Nine species of fiddler crabs (Crustacea: Ocypodidae: Gelasiminae) are known from the Arabian Sea and adjacent waters (Red Sea, Gulf of Aden, Gulf of Oman and Arabian/Persian Gulf): five species of Austruca, one Cranuca, two Gelasimus and one Tubuca. COI sequence data match morphological species boundaries and shows high connectivity within each. The fauna is highly endemic, with three species of Austruca (A. albimana, A. iranica and A. sindensis) confined to this region, and four others restricted to the Indian Ocean. restricted to the Indian Ocean. Austruca albimana and A. iranica speciated locally and now have narrowly overlapping ranges in Oman. Our results confirm the westernmost distributions of Austruca annulipes and Tubuca alcocki are Pakistan and the Red Sea, respectively. A key for the nine species is also provided to help identification.

Population diversity of sheep bot fly, Oestrus ovis (Linné, 1758) (Diptera: Oestridae: Oestrinae), using SDS polyacrylamide gel electrophoresis.

The study was planned to evaluate the inter, and intra population genetic variation in general protein banding pattern in Oestrus ovis larvae, by using 10% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). The larvae were collected from slaughtered goats head from five different locations (AAS, PN, LA, GM, and BC) of Karachi, Pakistan. The data obtained was subjected to POPGENE (Population Genetic Analysis) software for analysis. The polymorphic loci within populations ranged from 45.45% to 90.91%. Polymorphic loci observed in all populations were 90.91%. The expected heterozygosity observed was 0.182 ± 0.096 in all populations. The chi-square test showed 5 out of 11 loci at H-W equilibrium. The overall fixation index (FST) value was 0.108, showing that the likelihood of subpopulations being differentiated from one another is about 11 percent. The gene flow value (Nm = 2.065) was higher, showing that genes flow occurs between populations. The values of genetic identity were greater, and genetic distance were smaller among all the populations, which means that all the populations were more alike and closer to each other. It was concluded that there was no sympatric and parapatric population differentiation observed among all the population of O. ovis and the populations of the five different locations were not genetically and reproductively isolated from each other.

Distribution profile of heavy metals and associated contamination trend with the sedimentary environment of Pakistan coast bordering the Northern Arabian Sea.

Spatiotemporal distributions of heavy metals (HMs) and their contamination status linked with the sedimentary environment were investigated in 2 monitoring years (MY-I and MY-II) along the Pakistan coast. The concentrations of HMs in sediments were analyzed through an atomic absorption spectrometer and presented the following order: Fe > Zn > Cu > Pb ≈ Cr > Ni > Co > Cd in MY-I and Fe > Cr > Zn > Ni > Cu > Pb > Co > Cd in MY-II. In the coastal sediments, all HMs surpassed the edges of shale values and sediment quality guidelines, excluding Fe. The burial flux (FB), mass inventory (MI), and deposition flux (FD) of HMs were evaluated and compared to explore the potential of sediments to adsorb and desorb the metals into the marine environment during the last decade. Metal-specific pollution indices (Igeo, EF, Cf, and Er) presented moderate contamination of Cu, Zn, Cr, Ni, and Co but considerable contamination of Pb and Cd in sediments. However, site-specific geoindicators (CD, RI, and PLI) signified the Sandspit as the highest polluted site along the coastal vicinity. Multivariate analyses via principal component analysis (PCA) and cluster analysis (CA) also highlighted the significant interactions between geochemical properties. The current study concluded the high pollution state toward the HMs and rendered the knowledge for policymaking and conserving the coastal and estuarine environment of Pakistan bordering the Northern Arabian Sea.

Assessment of some heavy metal accumulation and nutritional quality of shellfish with reference to human health and cancer risk assessment: a seafood safety approach.

This study was conducted to assess the proximate analysis (protein, carbohydrate, lipid, and moisture content) and concentration levels of metals (Zn, Cu, Cd, Pb, and Cr) in the muscles of selected shellfish (Portunus reticulatus, P. segnis, P. sanguinolentus, Scylla olivaceae, Penaeus monodon, and P. indicus) species. The concentration of metals showed significant difference (p > 0.05) among species. The detected concentrations of the analyzed heavy metals were below the daily intake and legal limits set by national and international standards. The THQs and CR index were calculated to evaluate the risk estimation of the metal contamination associated with the human health. The THQ values of all metals were below 1 in all species, indicated that there is no risk of adverse health effect, but the risk of elevated intakes of heavy metals adversely affecting food safety for the studied species. The CR index indicated that Cd and Pb caused the greatest cancer risk. The correlation and multivariate (principle component analysis) among metal concentration and nutritional quality were also evaluated. The carbohydrate and moisture showed the positive correlation (p > 0.05) with metals. The biochemical results of the present work clearly indicate that there was a significant difference in the muscles of shellfish. It was concluded that more effective controls should be focused on Cd and Pb to reduce pollution for quality and seafood safety concern.

Occurrence of heavy metals in sediment and their bioaccumulation in sentinel crab (Macrophthalmus depressus) from highly impacted coastal zone.

The current study aimed to investigate the eight heavy metals (Fe, Cu, Zn, Cr, Ni, Co, Pb, and Cd) occurrence and risk assessment in the sediment and sentinel crab (Macrophthalmus depressus) from the mangrove and coastal environment of industrialized and mega city Karachi, Pakistan. The sediment analyzed for physiochemical properties (grain size composition, organic matter, and heavy metals), that presented significant variability (p < 0.05) among the selected sites. The environmental health and eco-toxicological profile of the habitat determined through the enrichment factor (EF), adverse effect index (AEI) and potential ecological risk index (RI) that revealed high anthropogenic influences along the Karachi coast. All heavy metals in crab showed significant spatial differences (p < 0.001) and the strong correlation between the essential and non-essential metals. Sediment-biota accumulation factor (SBAF) suggested active bio-accumulation (>1.0) in crabs for all metals, except Cr. Pb accumulation in crabs showed a significant increase (p < 0.05) with the exposure Pb levels in sediment, which indicated the potential of crab as a bioindicator of Pb contamination. Principal component analysis (PCA) concluded that environmental factors like seawater temperature, salinity, sediment grain size and organic matter had a significant association with different metal accumulation in crabs. The current study revealed the ecological significance of sentinel crab, M. depressus, as they endure with wide range (low to serious RI) of metal contaminated environment.

Re description and molecular identification of Thalamita danae (Stimpson 1858) (Decapoda: Brachyura: Portunidae) based on fresh material from the coastal waters, Pakistan.

Thalamita danae (Stimpson1858), re-described as a new report, based on an integrative taxonomy approach combining 16S rRNA partial sequence of mitochondrial DNA and morphological analyses was used for the accurate identification of specimens. The morphological and molecular analysis provides the confirm evidence of T. danae in coastal waters of Pakistan. Results were confirmed by amplification of partial sequences of 16S rRNA mt-DNA gene and the sequence was searched for similarity using BLASTn (Basic Local Alignment Tool), the result showed 97% sequence similarity with partial sequences of T. danae Stimpson, 1858 as obtained from gene bank. The attained sequence was submitted to gene bank after confirmation of genetic and morphological similarity. High sequence similarity with accession no: FJ152165.1 indicated, that misidentification of species does not occur.

Comparison of heavy metal contamination during the last decade along the coastal sediment of Pakistan: Multiple pollution indices approach.

Heavy metals concentrations (Fe, Cu, Zn, Ni, Cr, Co, Pb, and Cd) were scrutinized during two monitoring years (2001 and 2011) in the coastal sediment of Pakistan. The status of metal contamination in coastal sediment was interpreted using sediment quality guidelines, and single and combined metal pollution indices. Ni, Cr, and Cd were recognized for their significant (p<0.05) intensification in the sediment during the last decade. Sediment quality guidelines recognized the frequent adverse biological effect of Ni and the occasional adverse biological effect of Cu, Cr, Pb and Cd. Single metal pollution indices (Igeo, EF, CF, and ER) revealed that sediment pollution is predominantly caused by Pb and Cd. Low to moderate contamination was appraised along the coast by multi-metal pollution indices (CD and PERI). Correlation study specifies that heavy metals were presented diverse affiliations and carriers for distribution in the sediment during the last decade.

Population genetics of the fiddler crab Uca sindensis (Alcock, 1900) (Crustacea: Brachyura: Ocypodidae) from the Arabian Sea.

BACKGROUND: The fiddler crab Ucasindensis (Alcock, 1900) (Crustacea: Brachyura: Ocypodidae) is distributed in the northern coasts of the Arabian Sea (Pakistan, Iran, Iraq, and Kuwait). Its typical habitat is on high intertidal areas with higher salinity, which might restrict its distribution, especially within the Persian Gulf. The purpose of the present phylogeographicstudy is to understand whether the Strait of Hormuz acts as a barrier to the gene flow of this species. RESULTS: The genetic analyses of the mitochondrial 16S rRNA, cytochrome oxidase subunit I (COI), and control region (CR) of specimens from various localities showed that there was no genetic differentiation between the populations inside and outside of the Persian Gulf. CONCLUSIONS: We conclude that the narrow Strait of Hormuz does not form a barrier for the larval dispersal in this species. Its restricted distribution in the northern Arabian Sea may instead be associated with its preference for higher salinity sediments present in the coasts of thisregion.