Scalloped Hammerhead

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Kim N Holland - One of the best experts on this subject based on the ideXlab platform.

  • Scalloped Hammerhead sharks swim on their side with diel shifts in roll magnitude and periodicity
    Animal Biotelemetry, 2020
    Co-Authors: Mark A Royer, Kelsey Maloney, Carl G Meyer, Edward Cardona, Nicholas L Payne, Kate Whittingham, Guilherme Silva, Chloe Blandino, Kim N Holland
    Abstract:

    Great Hammerhead sharks (Sphyrna mokarran) routinely swim on their sides and periodically roll from side to side. A previous study used wind tunnel tests with a rigid model Hammerhead shark to demonstrate that the rolling behavior could improve swimming efficiency using the tall first dorsal fin as a lift-generating surface. Scalloped Hammerhead sharks (Sphyrna lewini) also have proportionally taller dorsal fins compared to pectoral fins than most shark species and similar to that of great Hammerhead sharks, and thus might exhibit similar rolling behavior. This was assessed by deploying multi-sensor accelerometer instrument packages on free-swimming adult Scalloped Hammerhead sharks to directly measure swimming depth, body orientation and swimming performance. Specific objectives were to (1) determine whether Scalloped Hammerhead sharks exhibit side swimming and rolling behavior, (2) characterize the patterns of these behaviors, and (3) evaluate the purpose of these behaviors. We obtained 196.7 total days (4720 h) of data from 9 free-swimming adult Scalloped Hammerhead sharks equipped with multi-instrument biologgers with deployment durations ranging from 7 to 29 days. All sharks exhibited rolling behavior throughout the entire period of observation. The roll angle magnitude and periodicity of rolling showed a clear diel pattern. During daytime, the sharks spent an average of 48% of the time swimming at a roll angle > 30°, with an average roll angle of 41° and rolling periodicity of around 4 min. At night, the sharks spent an average 82% of their time at an angle > 30°, with an average roll angle of 60° and rolling periodicity of around 13 min. In addition to an increase in degree of roll and roll duration, overall dynamic body acceleration (ODBA) also increased at night, and tailbeat frequency was more regular and consistent than during daytime. We observed rolling behavior in Scalloped Hammerhead sharks similar to that observed in great Hammerhead sharks. The diel changes in roll angle and periodicity were accompanied by other changes in swimming behavior. These changes are possibly due to interplay between reducing cost of transport and social interactions with conspecifics.

  • global phylogeography with mixed marker analysis reveals male mediated dispersal in the endangered Scalloped Hammerhead shark sphyrna lewini
    PLOS ONE, 2012
    Co-Authors: Toby S Dalyengel, Holly A Nance, Kanesa Duncan Seraphin, John P Coffey, Robert J Toonen, Kim N Holland, Brian W Bowen
    Abstract:

    Background The Scalloped Hammerhead shark, Sphyrna lewini, is a large endangered predator with a circumglobal distribution, observed in the open ocean but linked ontogenetically to coastal embayments for parturition and juvenile development. A previous survey of maternal (mtDNA) markers demonstrated strong genetic partitioning overall (global ΦST = 0.749) and significant population separations across oceans and between discontinuous continental coastlines. Methodology/Principal Findings We surveyed the same global range with increased sample coverage (N = 403) and 13 microsatellite loci to assess the male contribution to dispersal and population structure. Biparentally inherited microsatellites reveal low or absent genetic structure across ocean basins and global genetic differentiation (FST = 0.035) over an order of magnitude lower than the corresponding measures for maternal mtDNA lineages (ΦST = 0.749). Nuclear allelic richness and heterozygosity are high throughout the Indo-Pacific, while genetic structure is low. In contrast, allelic diversity is low while population structure is higher for populations at the ends of the range in the West Atlantic and East Pacific. Conclusions/Significance These data are consistent with the proposed Indo-Pacific center of origin for S. lewini, and indicate that females are philopatric or adhere to coastal habitats while males facilitate gene flow across oceanic expanses. This study includes the largest sampling effort and the most molecular loci ever used to survey the complete range of a large oceanic predator, and findings emphasize the importance of incorporating mixed-marker analysis into stock assessments of threatened and endangered shark species.

  • nursery habitat use and foraging ecology of the brown stingray dasyatis lata determined from stomach contents bulk and amino acid stable isotopes
    Marine Ecology Progress Series, 2011
    Co-Authors: Jonathan J. Dale, Natalie J Wallsgrove, Brian N Popp, Kim N Holland
    Abstract:

    Identification of nursery habitats and knowledge of the trophic ecology and habitat use of juvenile fishes within these habitats are fundamental in developing sound management and con- servation strategies. The brown stingray Dasyatis lata is a large benthic predator that inhabits the coastal waters of Hawai'i. Although abundant in these ecosystems, little is known about its basic eco - logy. Stomach content, bulk and amino acid stable isotope analyses were used to assess diet and habitat use of juvenile brown stingrays and to examine the possibility of competitive interactions with juvenile Scalloped Hammerhead sharks Sphyrna lewini that are sympatric with brown stingrays in K¯ ane'ohe Bay, Oahu. Based on stomach contents, brown stingrays fed almost exclusively on crus- taceans. An ontogenetic shift in stingray diet and an increase in relative trophic position (TP) were apparent from stomach content and stable isotope analysis. Stingray bulk δ 13 C and δ 15 N values indi- cated long-term foraging fidelity to subregions of the bay. Use of K¯ ane'ohe Bay as a nursery habitat was supported by nitrogen isotopic analysis of individual amino acids from stingray muscle samples. Our results clearly demonstrated that stingrays foraged within the bay for the majority of their juve- nile lives then shifted to offshore habitats with the onset of sexual maturity. Trophic enrichment fac- tors used to estimate TPs from amino acid analysis in previous studies may underestimate TPs in elas- mobranchs owing to urea retention for osmoregulation. Potential prey resources were partitioned between stingrays and juvenile Scalloped Hammerhead sharks, and TP estimates from each analyti- cal method indicated that juvenile Scalloped Hammerhead sharks forage on higher TP prey than do juvenile brown stingrays. These results show that the study of foraging ecology and habitat use of marine animals can greatly benefit from integrating traditional stomach content and bulk stable isotopic analyses with nitrogen isotopic analyses of individual amino acids.

  • habitat use growth rates and dispersal patterns of juvenile Scalloped Hammerhead sharks sphyrna lewini in a nursery habitat
    Marine Ecology Progress Series, 2006
    Co-Authors: Kanesa M Duncan, Kim N Holland
    Abstract:

    Nursery habitat use and growth rates of juvenile Scalloped Hammerhead sharks Sphyrna lewini were measured in a Hawai'i nursery (Kane'ohe Bay, O ¯ 'ahu) using a 28 mo tag-and- recapture study augmented by experimental determination of the relative age of neonate sharks. An estimated 7700 (±2240 SD) Hammerhead sharks are born in Kane'ohe Bay each year. Neonates are born in the summer between May and September and had low retention (from 0.07 to 0.15, as a frac- tion of neonate population size) within the bay from Age 0 to Age 1. A primary cause of low retention appears to be mortality from starvation. Most juvenile sharks recaptured after short periods of time at liberty (<60 d) showed weight loss. There was also a significant negative relationship between shark weight and umbilical wound condition. Sharks with healed wounds had lower average body weights than sharks with open wounds, indicating that many sharks lose weight in the first few weeks after birth. Shark condition factor (body weight × length -3 ) was also significantly lower during late summer and early fall. Despite this apparent lack of foraging success, growth rates and size distribution of recaptured sharks indicated that juvenile S. lewini utilize Kane'ohe Bay for up to 1 yr. During their residency, sharks move throughout the nursery and there is no discernible ontogenetic shift in habi- tat use. These findings confirmed recent hypotheses that Kane'ohe Bay may be more important in providing protection from predators than in providing a plentiful source of food for juvenile S. lewini.

  • diel movement patterns of the hawaiian stingray dasyatis lata implications for ecological interactions between sympatric elasmobranch species
    Marine Biology, 2003
    Co-Authors: Daniel P Cartamil, Christopher G Lowe, Jeremy J Vaudo, Bradley M Wetherbee, Kim N Holland
    Abstract:

    The Hawaiian stingray, Dasyatis lata, is a common benthic elasmobranch in nearshore Hawaiian waters. Acoustic telemetry was used to track the movements of seven rays in Kaneohe Bay, Oahu, Hawaii. Rays were tracked continuously over 31–74 h periods. Geographical movements were analyzed to determine space utilization and rate of movement. Rays were found to utilize significantly larger activity spaces at night (0.83±0.70 km2) (mean±SD) than during the day (0.12±0.15 km2). Mean total activity space for rays tracked was 1.32±0.75 km2. Rates of movement were also significantly higher at night (0.34±0.30 km h-1) than during the day (0.15±0.22 km h-1). Average straight-line swimming speed was 0.64±0.16 km h-1, with a maximum observed swimming speed of 1.9 km h-1. Tidal stage had no effect on rate of movement. Comparison with previously published data on juvenile Scalloped Hammerhead sharks, Sphyrna lewini, in Kaneohe Bay revealed a high degree of overlap in habitat use and time of activity, suggesting possible ecological interactions between these two species.

Ciro Rico - One of the best experts on this subject based on the ideXlab platform.

  • dna analysis of juvenile Scalloped Hammerhead sharks sphyrna lewini griffith 1834 reveals multiple breeding populations and signs of adaptive divergence in the south pacific
    Frontiers in Marine Science, 2019
    Co-Authors: Ciro Rico, Amandine D Marie, Brian Stockwell
    Abstract:

    Shark species have undergone drastic population declines in recent decades due to overfishing and habitat destruction; thus, establishing connectivity among the populations of various shark species is important to determine the appropriate units and spatial scale for conservation and management, particularly as this group is long-lived with late age of maturation. Consequently, we used DNA variation at 1,317 putatively neutral and 25 potentially adaptive single nucleotide polymorphisms (SNPs) to analyze population genetic structure among 174 unrelated individuals of Scalloped Hammerhead sharks (Sphyrna lewini) from the Rewa Delta and the Ba Estuary, where documented aggregations of neonates and young-of-the-year occur in the island of Viti Levu, Republic of Fiji. Results of the pairwise FST analysis for the neutral loci revealed a small but significant genetic differentiation (FST: 0.004; P-value = 0.0009). Furthermore, the 25 potentially adaptive loci (i.e. under putative selection) revealed a magnitude of differentiation four times bigger than the estimate obtained using neutral genetic diversity (FST: 0.017; P-value = 0.0009). Interestingly, population assignment tests, using the neutral SNP data set and two different software packages, Admixture and assignPOP, provided evidence for the existence of up to four genetically differentiated populations among our samples. Assignment probabilities ranged from 0.98 ± 0.01 to 0.81 ± 0.03. Admixture and assignPOP assigned the same individuals to the same putative populations for all sampled neonates. Thus, our results provide unequivocal evidence that adult females from multiple genetically differentiated breeding populations contribute to these juvenile aggregation sites.

  • first reconstruction of kinship in a Scalloped Hammerhead shark aggregation reveals the mating patterns and breeding sex ratio
    Frontiers in Marine Science, 2019
    Co-Authors: Amandine D Marie, Christophe M Herbinger, Ciro Rico, Philippe Fullsack
    Abstract:

    Sharks constitute one of the most threatened clades (Selachimorpha) of all marine fish, and substantial management efforts are required to help the recovery of their populations worldwide. Despite its significant impact on population dynamics and conservation, sharks’ reproductive and philopatric behavior has received little attention in fisheries management. The Scalloped Hammerhead shark (Sphyrna lewini), an endangered species listed on the IUCN’s Red List and on the CITES’ Appendix II, is an apex predator that potentially exhibits female philopatry to mating grounds. We reconstructed, for the first time in an open ocean species, the relationship among 166 juvenile individuals caught in a recently discovered aggregation of the Rewa Delta, Fiji, and determined the sample population’s mating system using 6,437 SNPs. Using two software packages, COLONY2 and SNP PEDIGREE, results revealed very high consistency in the identification of full and half sib. Moreover, COLONY2 allowed us to identify an equal breeding sex ratio for each cohort analyzed for this population (1.04:1; 1.02:1), as well as several cases of multiple paternity and numerous matings of the same male with different females suggesting polygynandry for this species. These findings reveal additional information about the complex life history of the Scalloped Hammerhead shark.

  • Community profiling of the intestinal microbial community of juvenile Hammerhead Sharks (Sphyrna lewini) from the Rewa Delta, Fiji
    Scientific Reports, 2019
    Co-Authors: Natacha M. S. Juste-poinapen, Marta Ferreira, Johann Poinapen, Lu Yang, Ciro Rico
    Abstract:

    Fourteen juvenile Scalloped Hammerhead sharks (Sphyrna lewini; SHS) were captured between November and December 2014 in the Rewa Delta in Fiji, and assessed for intestinal microflora characterisation using 16S rRNA amplicon sequencing by Illumina Miseq. The microbial population revealed a fluctuating dominance between the Enterobacteriaceae and Vibrionaceae families, namely Citrobacter and Photobacterium spp. Other related marine operational taxonomic units were closely related to Afipia felis, Chloroflexus aggregans, Psychrobacter oceani, Pontibacter actiniarum and Shigella sonnei. Two sharks had distinctive profiles that were dominated by known pathogens, namely Aeromonas salmonicida and Klebsiella pneumonia. The presence of a Methanosaeta species, and of Shigella and Psychrobacter, would suggest sewage contamination because of a spill that occurred on the 6th of December 2014. This study successfully establishes a baseline for future research.

  • Fisheries-independent surveys identify critical habitats for young Scalloped Hammerhead sharks (Sphyrna lewini) in the Rewa Delta, Fiji.
    Scientific Reports, 2017
    Co-Authors: Amandine D Marie, Cara Miller, Celso Cawich, Susanna Piovano, Ciro Rico
    Abstract:

    Sharp declines in numerous shark populations around the world have generated considerable interest in better understanding and characterising their biology, ecology and critical habitats. The Scalloped Hammerhead shark (SHS, Sphyrna lewini) is subject to a multitude of natural and anthropogenic threats that are often exacerbated within the coastal embayments and estuaries used during SHS early life stages. In this study, we describe the temporal and spatial distribution, age class composition, and reproductive biology of SHS in the Rewa Delta (RD), Fiji. A total of 1054 SHS (including 796 tagged individuals; 101 of which were recaptured) were captured from September 2014 to March 2016 in the RD. A majority of the captures in this area were neonates and young-of-the-year (YOY) (99.8%). Significant seasonality in patterns of occurrence of both neonates and YOY individuals suggests a defined parturition period during the austral summer. Between the seven sampling sites in the RD we also found significant differences in SHS neonate catch per unit of effort, and average total length of individuals. According to the data, the RD is likely to represent an important nursery area for SHS up to one year of age.

Felipe Galvanmagana - One of the best experts on this subject based on the ideXlab platform.

  • reproductive biology of the Scalloped Hammerhead sphyrna lewini in the central eastern pacific ocean
    Journal of the Marine Biological Association of the United Kingdom, 2021
    Co-Authors: Colombo Estupinanmontano, Maribel Carrerafernandez, Felipe Galvanmagana
    Abstract:

    There are limited data regarding the reproductive biology of the Scalloped Hammerhead (Sphyrna lewini) in Ecuadorian waters, which limits the development of appropriate management measures of its populations. A total of 1664 S. lewini specimens were recorded in Manta, Ecuador in 2003–2009. Specimens were caught by local commercial fisheries and measured between 50–310 cm total length (TL). Females were more frequently caught, with a sex ratio of 1M:1.8F. The median size at maturity was 178.1 cm TL for males and 219.4 cm TL for females, which was larger compared with other localities. Gravid females, which measured 246–298 cm TL, contained 16–22 embryos. Embryos, which were observed from October–July, measured between 11.1–54.6 cm TL and the available data agreed with a gestation period of 10–11 months that starts in September and ends in June/July. Size at birth was 47–55 cm TL. Sampling data indicated that most fishing activity occurred in nearshore and around seamounts in the central-eastern Pacific Ocean, with much of the landed catch comprising immature individuals. This study documents the reproductive biology of S. lewini in the central-eastern Pacific Ocean and provides additional information to improve management and conservation measures for this species.

  • diet comparison between silky sharks carcharhinus falciformis and Scalloped Hammerhead sharks sphyrna lewini off the south west coast of mexico
    Journal of the Marine Biological Association of the United Kingdom, 2016
    Co-Authors: Isaac Antonio Floresmartinez, Yassir Eden Torresrojas, Felipe Galvanmagana, Julia Ramosmiranda
    Abstract:

    Ecologists examine diet composition in order to assess the spatial and temporal variations in interactions between species, the impact of different species traits on the ecological network structure, and the long-term effects of the removal of different species by small-scale fisheries. In this study, our goal was to compare the diets of silky sharks ( Carcharhinus falciformis ) and Scalloped Hammerhead sharks ( Sphyrna lewini ) off the south-west coast of Mexico in order to infer their diet preferences and spatial distributions. We sampled 164 S. lewini (96 stomachs had food, 68 were empty) and 183 C. falciformis (30 stomachs had food, 153 were empty) in Puerto Madero, Chiapas in 2011. The large number of empty stomachs may be the result of using longline fishing gear, which causes high stress resulting in regurgitation. Based on the index of relative importance (%IRI), the fish Chloroscombrus orqueta (IIR = 27.7%) was the most important species in the diet of S. lewini , while the squid Dosidicus gigas (IIR = 34%) was the primary prey of C. falciformis . Levin's index (Bi) and Shannon's index (H′) confirm that both sharks are generalists, as in other regions. The trophic levels of S. lewini (TL = 4.1) and C. falciformis (TL = 4.2) are characteristic of tertiary consumers; meanwhile, the Morisita–Horn index indicates low interspecific overlap between all categories. These results confirm that these two sharks have different foraging preferences or movement patterns; thus, there is no trophic overlap between species as they play unique roles in the ecological network off the south-west coast of Mexico.

  • mercury and selenium in muscle and target organs of Scalloped Hammerhead sharks sphyrna lewini of the se gulf of california dietary intake molar ratios loads and human health risks
    Archives of Environmental Contamination and Toxicology, 2015
    Co-Authors: Magdalena E Bergestiznado, Yassir Eden Torresrojas, Felipe Galvanmagana, Fernando Marquezfarias, Raul E Laramendoza, Humberto Bojorquezleyva, Federico Paezosuna
    Abstract:

    Selenium and mercury were evaluated in muscle, liver, kidney, brain, and the stomach contents of juvenile Scalloped Hammerhead shark Sphyrna lewini. Se:Hg molar ratios were calculated. The average Hg levels in muscle ranged from 0.12 to 1.17 μg/g (wet weight); Hg was 1. Correlations were found for Hg in muscle with size, age, and weight, and also for Hg in liver with size, age, and weight. Hg in muscle was significantly positive correlated to Hg in brain as well as Hg in liver was correlated to Hg in kidney. The highest Hg in preys was for carangid fishes; scombrid and carangid fishes contributed with the highest Se levels. Results suggest that more than 98 % of the total Hg and 62 % of Se end up in muscle and might be affected by factors, such as geographical area, age, size, and feeding habits. The muscle of S. lewini should be consumed by people cautiously so as not to exceed the recommended intake per week.

  • ontogenetic migration of a female Scalloped Hammerhead shark sphyrna lewini in the gulf of california
    Animal Biotelemetry, 2014
    Co-Authors: Mauricio E Hoyospadilla, Peter A Klimley, Felipe Galvanmagana
    Abstract:

    Little information exists on the vertical and horizontal movements of juvenile Scalloped Hammerhead sharks (Sphyrna lewini). Measurements of the sizes of juveniles caught in nets close to shore and those swimming in schools at seamounts and islands in the southwestern Gulf of California, Mexico indicate that at least part of the population undergoes a migration during their life cycle at a length of approximately 115 cm total length (TL) from coastal to offshore waters. Three juvenile Hammerhead sharks were outfitted with archival tags in Mazatlan and La Paz Bay (LPB), Mexico during February 2006 and January 2007, respectively. A single juvenile female measuring 95 cm TL tagged in LPB was recaptured. It traveled a distance of approximately 3,350 km during a 10.5-month period from LPB northward to the central Gulf of California and returning to LPB, 11.7 km north of the location it was tagged. During this migration, the Hammerhead increasingly moved from shallow coastal waters to deeper waters to possibly maximize its foraging success. After moving offshore, the shark remained in shallow and warm waters of less than 30 m depth and as high as 32°C during the day, and made repeated dives to deeper and colder waters of 250 m depth and 11°C, at night. Our study documents a female Scalloped Hammerhead shark changing life history phases from a nursery-inhabiting juvenile inshore to a migratory sub-adult offshore. We also infer that this shark swam within a school of conspecifics at an offshore island or seamount during the day, and migrated away at night, diving to greater depths to feed on mesopelagic prey. We show that this female shark carried out her complete biological cycle in both coastal and offshore areas of the central and southwestern Gulf of California, suggesting maximization of foraging opportunities and continued growth. In this study, we provide evidence for the first time of an ontogenetic migration of a juvenile Scalloped Hammerhead shark in the Gulf of California, which could be of great significance for the regional management and conservation of sharks in the Gulf of California.

  • ontogenetic migration of a female Scalloped Hammerhead shark sphyrna lewini in the gulf of
    2014
    Co-Authors: Mauricio E Hoyospadilla, Peter A Klimley, Felipe Galvanmagana
    Abstract:

    Background: Little information exists on the vertical and horizontal movements of juvenile Scalloped Hammerhead sharks (Sphyrna lewini). Measurements of the sizes of juveniles caught in nets close to shore and those swimming in schools at seamounts and islands in the southwestern Gulf of California, Mexico indicate that at least part of the population undergoes a migration during their life cycle at a length of approximately 115 cm total length (TL) from coastal to offshore waters. Three juvenile Hammerhead sharks were outfitted with archival tags in Mazatlan and La Paz Bay (LPB), Mexico during February 2006 and January 2007, respectively. Results: A single juvenile female measuring 95 cm TL tagged in LPB was recaptured. It traveled a distance of approximately 3,350 km during a 10.5-month period from LPB northward to the central Gulf of California and returning to LPB, 11.7 km north of the location it was tagged. During this migration, the Hammerhead increasingly moved from shallow coastal waters to deeper waters to possibly maximize its foraging success. After moving offshore, the shark remained in shallow and warm waters of less than 30 m depth and as high as 32°C during the day, and made repeated dives to deeper and colder waters of 250 m depth and 11°C, at night. Conclusions: Our study documents a female Scalloped Hammerhead shark changing life history phases from a nursery-inhabiting juvenile inshore to a migratory sub-adult offshore. We also infer that this shark swam within a school of conspecifics at an offshore island or seamount during the day, and migrated away at night, diving to greater depths to feed on mesopelagic prey. We show that this female shark carried out her complete biological cycle in both coastal and offshore areas of the central and southwestern Gulf of California, suggesting maximization of foraging opportunities and continued growth. In this study, we provide evidence for the first time of an ontogenetic migration of a juvenile Scalloped Hammerhead shark in the Gulf of California, which could be of great significance for the regional management and conservation of sharks in the Gulf of California.

Hawis H. Madduppa - One of the best experts on this subject based on the ideXlab platform.

  • genetic connectivity of the Scalloped Hammerhead shark sphyrna lewini across indonesia and the western indian ocean
    PLOS ONE, 2020
    Co-Authors: Sutanto Hadi, Mohammad Ichsan, B M Simeon, Effin Muttaqin, Noviar Andayani, Beginer Subhan, Hawis H. Madduppa
    Abstract:

    Scalloped Hammerhead shark (Sphyrna lewini) is an endangered species which its populations have been declining globally including in Indonesia, the world's top shark fishing country. However, there is a lack of information on the recent population structure of this species to promote proper management and its conservation status. This study aimed to investigate the genetic diversity, population structure, and connectivity of the S. lewini population, in three major shark landing sites: Aceh (n = 41), Balikpapan (n = 30), and Lombok (n = 29). Meanwhile, additional sequences were retrieved from West Papua (n = 14) and the Western Indian Ocean (n = 65) populations. From the analyses of the mitochondrial CO1 gene, a total of 179 sequences of S. lewini, with an average size of 594 bp, and 40 polymorphic loci in four and eight haplotypes for the Indonesian population and the Western Indian Ocean population were identified. The overall values of genetic diversity were high (h = 0.717; π = 0.013), with the highest values recorded in Aceh (h = 0.668; π = 0.002) and the lowest in Papua (h = 0.143; π = 0.000). On the contrary, the overall value was fairly low in the Western Indian Ocean (h = 0.232; π = 0.001). Furthermore, AMOVA and FST showed three significant subdivisions in Indonesia (FST = 0.442; P < 0.001), with separated populations for Aceh and West Papua, and mixed between Balikpapan and Lombok (FST = 0.044; P = 0.091). In contrast, genetic homogeneity was observed within the population of the Western Indian Ocean (FST = -0.013; P = 0.612). The establishment of a haplotype network provided evidence of a significantly different population and a limited genetic distribution between the Indonesian and the Western Indian Ocean populations (FST = 0.740; P < 0.001). This study showed the presence of a complex population of S. lewini with limited connectivity only in Indonesia separated from the Western Indian Ocean and requiring specific management measures based on the population structure at the regional level.

  • genetic connectivity and diversity of endangered species the Scalloped Hammerhead shark sphyrna lewini griffith smith 1834 population in indonesia and western indian ocean
    bioRxiv, 2020
    Co-Authors: Hawis H. Madduppa, Mohammad Ichsan, B M Simeon, Effin Muttaqin, Sutanto Hadi, Noviar Andayani, Beginer Subhan
    Abstract:

    The Scalloped Hammerhead shark Sphyrna lewini is an endangered species which expected to population declined worldwide including in Indonesia due to overexploited. However, there is a lack of information regarding recent population structure to promote proper management and conservation status in Indonesia. This study aimed to investigate the genetic diversity, population structure and connectivity of S. lewini population in Indonesia from three major sharks landing sites in Aceh (n= 41), Balikpapan (n= 30), Lombok (n= 29), and additional sequences retrieved from West Papua (n= 14) and Western Indian Ocean population (n= 65). Analyses of mitochondrial CO1 gene successfully identified a total of 179 sequences of S. lewini with an average 594 bp nucleotide with 40 polymorphic loci in 4 haplotypes for Indonesian population and 8 haplotypes for Western Indian Ocean. The overall values of genetic diversity in Indonesia was high (Hd= 0.7171; π= 0.0126), with the highest was in Aceh (Hd= 0.6683; π= 0.0198), and the lowest was in Papua (Hd= 0.1429; π= 0.0005), while in Western Indian Ocean the overall value was fairly low (Hd= 0.2322; π= 0.0010). The AMOVA and FST revealed three significant population subdivisions in Indonesia (FST= 0.4415; p

Noviar Andayani - One of the best experts on this subject based on the ideXlab platform.

  • genetic connectivity of the Scalloped Hammerhead shark sphyrna lewini across indonesia and the western indian ocean
    PLOS ONE, 2020
    Co-Authors: Sutanto Hadi, Mohammad Ichsan, B M Simeon, Effin Muttaqin, Noviar Andayani, Beginer Subhan, Hawis H. Madduppa
    Abstract:

    Scalloped Hammerhead shark (Sphyrna lewini) is an endangered species which its populations have been declining globally including in Indonesia, the world's top shark fishing country. However, there is a lack of information on the recent population structure of this species to promote proper management and its conservation status. This study aimed to investigate the genetic diversity, population structure, and connectivity of the S. lewini population, in three major shark landing sites: Aceh (n = 41), Balikpapan (n = 30), and Lombok (n = 29). Meanwhile, additional sequences were retrieved from West Papua (n = 14) and the Western Indian Ocean (n = 65) populations. From the analyses of the mitochondrial CO1 gene, a total of 179 sequences of S. lewini, with an average size of 594 bp, and 40 polymorphic loci in four and eight haplotypes for the Indonesian population and the Western Indian Ocean population were identified. The overall values of genetic diversity were high (h = 0.717; π = 0.013), with the highest values recorded in Aceh (h = 0.668; π = 0.002) and the lowest in Papua (h = 0.143; π = 0.000). On the contrary, the overall value was fairly low in the Western Indian Ocean (h = 0.232; π = 0.001). Furthermore, AMOVA and FST showed three significant subdivisions in Indonesia (FST = 0.442; P < 0.001), with separated populations for Aceh and West Papua, and mixed between Balikpapan and Lombok (FST = 0.044; P = 0.091). In contrast, genetic homogeneity was observed within the population of the Western Indian Ocean (FST = -0.013; P = 0.612). The establishment of a haplotype network provided evidence of a significantly different population and a limited genetic distribution between the Indonesian and the Western Indian Ocean populations (FST = 0.740; P < 0.001). This study showed the presence of a complex population of S. lewini with limited connectivity only in Indonesia separated from the Western Indian Ocean and requiring specific management measures based on the population structure at the regional level.

  • genetic connectivity and diversity of endangered species the Scalloped Hammerhead shark sphyrna lewini griffith smith 1834 population in indonesia and western indian ocean
    bioRxiv, 2020
    Co-Authors: Hawis H. Madduppa, Mohammad Ichsan, B M Simeon, Effin Muttaqin, Sutanto Hadi, Noviar Andayani, Beginer Subhan
    Abstract:

    The Scalloped Hammerhead shark Sphyrna lewini is an endangered species which expected to population declined worldwide including in Indonesia due to overexploited. However, there is a lack of information regarding recent population structure to promote proper management and conservation status in Indonesia. This study aimed to investigate the genetic diversity, population structure and connectivity of S. lewini population in Indonesia from three major sharks landing sites in Aceh (n= 41), Balikpapan (n= 30), Lombok (n= 29), and additional sequences retrieved from West Papua (n= 14) and Western Indian Ocean population (n= 65). Analyses of mitochondrial CO1 gene successfully identified a total of 179 sequences of S. lewini with an average 594 bp nucleotide with 40 polymorphic loci in 4 haplotypes for Indonesian population and 8 haplotypes for Western Indian Ocean. The overall values of genetic diversity in Indonesia was high (Hd= 0.7171; π= 0.0126), with the highest was in Aceh (Hd= 0.6683; π= 0.0198), and the lowest was in Papua (Hd= 0.1429; π= 0.0005), while in Western Indian Ocean the overall value was fairly low (Hd= 0.2322; π= 0.0010). The AMOVA and FST revealed three significant population subdivisions in Indonesia (FST= 0.4415; p

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