scholarly journals Fatal Infection in a Wild Sandbar Shark (Carcharhinus plumbeus), Caused by Streptococcus agalactiae, Type Ia-ST7

Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 284
Author(s):  
Danny Morick ◽  
Nadav Davidovich ◽  
Eyal Bigal ◽  
Ezra Rosenbluth ◽  
Arieli Bouznach ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Streptococcus Agalactiae ◽  
Pathogenic Bacteria ◽  
Molecular Techniques ◽  
Shark Species ◽  
Post Mortem ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Type Ia ◽  
Important Fish

Streptococcus agalactiae is one of the most important fish pathogenic bacteria as it is responsible for epizootic mortalities in both wild and farmed species. S. agalactiae is also known as a zoonotic agent. In July 2018, a stranded wild sandbar shark (Carcharhinus plumbeus), one of the most common shark species in the Mediterranean Sea, was found moribund on the seashore next to Netanya, Israel, and died a few hours later. A post-mortem examination, histopathology, classical bacteriology and advanced molecular techniques revealed a bacterial infection caused by S. agalactiae, type Ia-ST7. Available sequences publicly accessible databases and phylogenetic analysis suggest that the S. agalactiae isolated in this case is closely related to fish and human isolates. To the best of our knowledge, this is the first description of a fatal streptococcosis in sandbar sharks.

Demography of the central california population of the Leopard Shark (Triakis semifasciata)

1992 ◽  
Vol 43 (1) ◽  
pp. 183 ◽  
Author(s):  
GM Cailliet
Keyword(s):  
Population Growth ◽  
Reproductive Rate ◽  
Shark Species ◽  
Sandbar Shark ◽  
Lemon Shark ◽  
Carcharhinus Plumbeus ◽  
Net Reproductive Rate ◽  
Leopard Shark ◽  
Triakis Semifasciata ◽  
Leopard Sharks

Demographic analyses can be quite useful for effectively managing elasmobranch fisheries. However, they require valid estimates of age-specific mortality and natality rates, in addition to information on the distribution, abundance, habits and reproduction of the population, to produce reliable estimates of population growth. Because such detailed ecological information is usually unavailable, complete demographic analyses have been completed for only four shark species: the spiny dogfish, Squalus acanthias; the soupfin shark, Galeorhinus australis; the lemon shark, Negaprion brevirostris; and most recently the sandbar shark, Carcharhinus plumbeus. In California, reliable estimates of age, growth, mortality, age at maturity, and fecundity are available only for the leopard shark, Triakis semifasciata. A demographic analysis of this species yielded a net reproductive rate (Ro) of 4.467, a generation time (G) of 22.35 years, and an estimate of the instantaneous population growth coefficient (r) of 0.067. If the mean fishing pressure over 10 years (F= 0.084) is included in the survivorship function, Ro and r are reduced considerably, especially if leopard sharks first enter the fishery at early ages. A size limit of 120 cm TL (estimated age 13 years), especially for female sharks, is tentatively proposed for the leopard shark fishery.

scholarly journals Patterns in abundance and size of sharks in northwestern Australia: cause for optimism

2019 ◽  
Vol 77 (1) ◽  
pp. 72-82
Author(s):  
Matias Braccini ◽  
Brett Molony ◽  
Nick Blay
Keyword(s):  
Life Histories ◽  
Shark Species ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Study Region ◽  
Scalloped Hammerhead ◽  
Carcharhinus Obscurus ◽  
Northwestern Australia ◽  
Mean Size ◽  
Catch Rates

Abstract Reliable information for population assessments is rare for sharks. We quantified patterns in catch rates and mean size for numerous tropical and subtropical species from 15 years of fishery-independent surveys (2002–2017) in northwestern Australia. This study region represents an area of ~0.8 million km2 which was closed to commercial shark fishing from 1993 or 2005 onward due to the very high State-wide catches of sandbar (Carcharhinus plumbeus) and dusky (Carcharhinus obscurus) sharks. A total of 43 shark and ray species were sampled, with sandbar shark being the most commonly caught species, followed by milk (Rhizoprionodon acutus), spot-tail (Carcharhinus sorrah), tiger (Galeocerdo cuvier), blacktip (Carcharhinus limbatus and Carcharhinus tilstoni), dusky and sliteye (Loxodon macrorhinus) sharks, and scalloped hammerhead (Sphyrna lewini). For sandbar shark, catch rates increased between 2008 and 2017 whereas for other taxa catch rates were mostly stable (albeit fluctuating). Mean size at capture fluctuated across years with no particular trends. Unlike for other parts of the world, catch rates and mean size of northwestern Australian sharks have been stable or increased in recent years. Though most shark species have conservative life histories, when science, management and enforcement work synergistically, sustainable resource use, recovery and conservation outcomes can all be achieved.

interpretation of vertebral growth marks as annuli in the sandbar shark carcharhinus plumbeus: analysis of vertebrae of captive specimens

2005 ◽  
Vol 85 (5) ◽  
pp. 1167-1170 ◽  
Author(s):  
borja torres ◽  
gabriel morey ◽  
javier tomás
Keyword(s):  
Adult Female ◽  
Shark Species ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Short Period ◽  
In Captivity ◽  
Juvenile Individual ◽  
Similar Distance ◽  
Pattern Distribution ◽  
Vertebral Growth

four captive specimens of sandbar shark carcharhinus plumbeus from the l'oceanogràfic aquarium (valencia, spain) were studied: one adult female (192 cm total length [tl]) reared for five months, her two new born pups (a female, 61 cm tl and a male, 60 cm tl), and one juvenile female, born in captivity, dead at nine months of age (90 cm tl). comparative measurements of length and diameter of vertebrae from three different regions of the vertebral column showed that vertebrae above the pelvic fins (nos. 59–63) are the biggest in this species. consequently, these vertebrae are preferred for age estimation given that growth marks are easier to identify. the only present mark in the vertebrae of the two neonate specimens was at the edge and was interpreted as the birth mark. a mark at a similar distance was present in the vertebrae of the juvenile and adult females.adult female vertebrae analysis shows 23 marks without any variation in the banding pattern distribution during free-range growth and short period of captivity. the juvenile individual shows two clear growth marks developed after birth. the presence of these marks in a 9-month old individual suggests that the counting of all vertebral growth marks as annuli may result in the overestimation of age for this shark species.

Frequency of multiple paternity in an unexploited tropical population of sandbar sharks (Carcharhinus plumbeus)

2007 ◽  
Vol 64 (2) ◽  
pp. 198-204 ◽  
Author(s):  
Toby S Daly-Engel ◽  
R Dean Grubbs ◽  
Brian W Bowen ◽  
Robert J Toonen
Keyword(s):  
Mating Systems ◽  
Multiple Paternity ◽  
The United States ◽  
Commercial Fishing ◽  
Shark Species ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Polymorphic Microsatellite ◽  
Gravid Females ◽  
The Impact

Elasmobranch mating systems have received growing attention in the past few years because of worldwide overexploitation of shark populations. Few studies to date have examined mating systems in sharks because of difficulty in sampling. The sandbar shark (Carcharhinus plumbeus) is heavily harvested around the world and is the dominant species in the main commercial fishery for large coastal sharks in the United States. In contrast, Hawaii hosts one of the few unexploited populations of sandbar sharks and represents an opportunity to gather data on the reproductive biology of a vulnerable shark species without the confounding effects of fishing mortality. We examined the frequency of multiple paternity in Hawaiian sandbar sharks using 130 individuals (20 gravid females with three–eight pups each per litter) surveyed with six polymorphic microsatellite loci and determined that 8 of the 20 litters (40%) were multiple- sired. A Bayesian approach estimated the frequency of multiple mating in this population at 43.8%, with a 95% confidence interval of 23%–63%. We conclude that multiple paternity and genetic monogamy occur with roughly equal frequency in the Hawaiian sandbar shark population. This study may serve as groundwork for understanding the impact of commercial fishing pressure on elasmobranch mating systems.

Developmental stages of Alebion lobatus Cressey, 1970 (Copepoda: Euryphoridae) found parasitic on the sandbar shark (Carcharhinus plumbeus (Nardo, 1827)) in the western North Atlantic, and a phylogenetic analysis of the genus Alebion Krøyer, 1863

1989 ◽  
Vol 67 (6) ◽  
pp. 1578-1598 ◽  
Author(s):  
George W. Benz
Keyword(s):  
Phylogenetic Analysis ◽  
Body Surface ◽  
North Atlantic ◽  
Developmental Stages ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Female Adult ◽  
Male And Female ◽  
Frontal Filament ◽  
Three Stages

Three stages of copepodids, two preadults, and male and female adult Alebion lobatus collected from sandbar sharks (Carcharhinus plumbeus) in the western North Atlantic are described. Copepodids were found on the external body surface of hosts in hollows which were apparently formed by the absence of one to several placoid scales. A frontal filament was not observed in any developmental stage and the second antennae appeared to be the primary prehensile appendages. Two equally most parsimonious cladograms are presented as hypotheses of phylogenetic relationship for the eight known species of Alebion.

scholarly journals Extract from phyllosphere bacteria with antibiofilm and quorum quenching activity to control several fish pathogenic bacteria

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Olivia Nathalia ◽  
Diana Elizabeth Waturangi
Keyword(s):  
Streptococcus Agalactiae ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Vibrio Harveyi ◽  
Quorum Quenching ◽  
Indicator Bacteria ◽  
Antibiofilm Activity ◽  
Fish Pathogen ◽  
Phyllosphere Bacteria

Abstract Objective The objective of this research were to screen quorum quenching activity compound from phyllosphere bacteria as well as antibiofilm activity against several fish pathogen bacteria such as Aeromonas hydrophila, Streptococcus agalactiae, and Vibrio harveyi. Results We found eight phyllosphere bacteria isolates with potential quorum quenching activity to inhibit Chromobacterium violaceum as indicator bacteria. Crude extracts (20 mg/mL) showed various antibiofilm activity against fish pathogenic bacteria used in this study. Isolate JB 17B showed the highest activity to inhibit biofilm formation of A. hydrophila and V. harveyi, meanwhile isolate JB 3B showed the highest activity to inhibit biofilm of S. agalactiae. From destruction assay, isolate JB 8F showed the highest activity to disrupt biofilm of A. hydrophila isolate JB 20B showed the highest activity to disrupt biofilm of V. harveyi, isolate JB 17B also showed the highest activity to disrupt biofilm of S. agalactiae.

World phylogeography and male-mediated gene flow in the sandbar shark, Carcharhinus plumbeus

2010 ◽  
Vol 19 (10) ◽  
pp. 1994-2010 ◽  
Author(s):  
DAVID S. PORTNOY ◽  
JAN R. MCDOWELL ◽  
EDWARD J. HEIST ◽  
JOHN A. MUSICK ◽  
JOHN E. GRAVES
Keyword(s):  
Gene Flow ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus

Shark Nursery Grounds of the Gulf of Mexico and the East Coast Waters of the United States

2007 ◽  
Keyword(s):  
South Carolina ◽  
The United States ◽  
North Inlet ◽  
Shark Species ◽  
Sandbar Shark ◽  
Catch Per Unit Effort ◽  
Salinity Regime ◽  
Carcharhinus Limbatus ◽  
Winyah Bay ◽  
The Impact

<em>Abstract.</em>—Winyah Bay is a 65-km<sup>2</sup> estuary in northeast South Carolina, and North Inlet is a 32- km<sup>2</sup>, high-salinity estuary connected to both Winyah Bay and the Atlantic Ocean. The objectives of this study were to survey the shark fauna of these systems, determine the potential of these estuaries as shark nurseries, and assess the impact of salinity structure on shark diversity and abundance in these two estuaries. From May to November in 2002 (a drier than average year) and 2003 (a wetter than average year), 227 bottom longlines (16/0 and 12/0 hooks) were set in Winyah Bay. In 2002 and 2003, a total of 119 trammel net sets were also conducted from June to October in North Inlet. A total of 196 sharks (38 adults, 158 juveniles) representing 10 species were captured in Winyah Bay in 2002, whereas 73 sharks (17 adults and 56 juveniles) representing four species were caught in 2003. Catch per unit effort (CPUE) for all sharks caught in Winyah Bay was not significantly different between 2002 and 2003. Blacktip shark <em>Carcharhinus limbatus </em>and finetooth shark <em>C. isodon </em>CPUE declined significantly on 16/0 hook longlines set in Winyah Bay from 2002 to 2003. For 12/0 hook longlines set in Winyah Bay, CPUE for three species (sandbar shark <em>C. plumbeus</em>, Atlantic sharpnose shark <em>Rhizoprionodon terraenovae</em>, and finetooth shark) out of five declined significantly from 2002 to 2003. Within Winyah Bay, CPUE for sharks on both longline configurations was not significantly different between lower and middle bay sites for 2002 but was for 2003. In both years, CPUE correlated positively with bottom salinity in Winyah Bay. In North Inlet, in 2002, 30 sharks (20 adults, 10 juveniles) comprising five species were caught, whereas 57 sharks (26 adults and 31 juveniles) representing three species were caught in 2003. The CPUE in 2002 was significantly less than in 2003 in North Inlet for Atlantic sharpnose sharks, bonnetheads <em>Sphyrna tiburo</em>, and all sharks combined. This study documented the presence of adults and juveniles (including neonates and young of the year) for 10 species of sharks in Winyah Bay and 5 in North Inlet and thus identified these areas as shark habitat and potential primary and secondary nurseries for some shark species. We also observed salinity-related differences in the distribution of sharks in both estuaries, including differences in abundance and age-class, as a result of normal salinity regime and precipitation-induced salinity changes.

Shark Nursery Grounds of the Gulf of Mexico and the East Coast Waters of the United States

2007 ◽  
Keyword(s):  
United States ◽  
Gulf Of Mexico ◽  
East Coast ◽  
Gulf Coast ◽  
Atlantic Coast ◽  
The United States ◽  
Shark Species ◽  
Carcharhinus Plumbeus ◽  
Nursery Areas ◽  
Pesticide Metabolites

<em>Abstract.</em>—Because of their tendency to accumulate in estuaries and coastal regions, organochlorine (OC) contaminants such as pesticides and polychlorinated biphenyls (PCBs) represent potential threats to the quality of essential fish habitat for many shark species. These compounds pose special risks to immature sharks in particular because of their ability to impair growth and sexual maturation in juvenile fish at environmentally relevant levels of exposure. In order to assess the extent of these risks in shark populations on the East Coast of the United States, the present study examined concentrations of 30 OC pesticides/pesticide metabolites and total PCBs in juvenile sandbar <em>Carcharhinus plumbeus </em>and blacktip <em>C. limbatus </em>sharks from seven major nursery areas in the western Atlantic Ocean and eastern Gulf of Mexico. Quantifiable levels of PCBs and 13 OC pesticides/ pesticide metabolites were detected via gas chromatography and mass spectrometry in liver of 25 young-of-the-year blacktip sharks from the southeastern U.S. Atlantic coast and three regions on Florida’s gulf coast: Cedar Key, Tampa Bay, and Charlotte Harbor. Similarly, quantifiable levels of PCBs and 14 OC pesticides/metabolites were detected in 23 juvenile <em>C. plumbeus </em>from three sites on the northeastern U.S. coast: middle Delaware Bay, lower Chesapeake Bay, and Virginia’s eastern shore. Liver OC concentrations in Atlantic sandbar and blacktip sharks were higher than expected and, in some cases, comparable with elevated levels observed in deep-sea and pelagic sharks. Although significantly lower than those observed in Atlantic sharks, pesticide and PCB levels in Florida blacktip sharks were similar to, if not greater than, OC concentrations reported in adults of other coastal shark species. Based on these data, OC contamination appears to pose significant threats to habitat quality in sandbar and blacktip shark nursery areas on the U.S. Atlantic coast.

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