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 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.

Revised Estimates of Age and Growth of the Sandbar Shark (Carcharhinus plumbeus) from the Western North Atlantic

1992 ◽  
Vol 49 (7) ◽  
pp. 1474-1477 ◽  
Author(s):  
John G. Casey ◽  
Lisa J. Natanson
Keyword(s):  
North Atlantic ◽  
Age And Growth ◽  
Von Bertalanffy ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus

Age and growth of the sandbar shark (Carcharhinus plumbeus) were determined from tag and recapture data covering a 26-yr period (1964–90). Results were compared with previously published age and growth estimates based primarily on rings in vertebrae. Recent long-term tag returns suggest that the sandbar shark grows much slower than previously proposed and may take nearly 30 yr to reach maturity. Revised von Bertalanffy parameters (sexes combined) are L∞ = 186, k = 0.046, and t0 = −6.45. The limitations of ageing elasmobranchs solely from rings in vertebrae and the need for validating rings in hardparts of fishes are discussed.

scholarly journals Selection and evaluation of reference genes for analysis of mouse(Mus musculus) sex-dimorphic brain development

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2909 ◽  
Author(s):  
Tanya T. Cheung ◽  
Mitchell K. Weston ◽  
Megan J. Wilson
Keyword(s):  
Gene Expression ◽  
Brain Development ◽  
Reference Gene ◽  
Reference Genes ◽  
Developmental Stages ◽  
Male And Female ◽  
Female Brain ◽  
Three Stages ◽  
Quantify Gene Expression ◽  
The Brain

The development of the brain is sex-dimorphic, and as a result so are many neurological disorders. One approach for studying sex-dimorphic brain development is to measure gene expression in biological samples using RT-qPCR. However, the accuracy and consistency of this technique relies on the reference gene(s) selected. We analyzed the expression of ten reference genes in male and female samples over three stages of brain development, using popular algorithms NormFinder, GeNorm and Bestkeeper. The top ranked reference genes at each time point were further used to quantify gene expression of three sex-dimorphic genes (Wnt10b,XistandCYP7B1). When comparing gene expression between the sexes expression at specific time points the best reference gene combinations are:Sdha/Pgk1at E11.5,RpL38/SdhaE12.5, andActb/RpL37at E15.5. When studying expression across time, the ideal reference gene(s) differs with sex. For XY samples a combination ofActb/Sdha. In contrast, when studying gene expression across developmental stage with XX samples,Sdha/Gapdhwere the top reference genes. Our results identify the best combination of two reference genes when studying male and female brain development, and emphasize the importance of selecting the correct reference genes for comparisons between developmental stages.

Genetic polyandry and sexual conflict in the sandbar shark, Carcharhinus plumbeus, in the western North Atlantic and Gulf of Mexico

2006 ◽  
Vol 16 (1) ◽  
pp. 187-197 ◽  
Author(s):  
DAVID S. PORTNOY ◽  
ANDREW N. PIERCY ◽  
JOHN A. MUSICK ◽  
GEORGE H. BURGESS ◽  
JOHN E. GRAVES
Keyword(s):  
Gulf Of Mexico ◽  
North Atlantic ◽  
Sexual Conflict ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus

Age and Growth of the Sandbar Shark (Carcharhinus plumbeus) from the Western North Atlantic

1985 ◽  
Vol 42 (5) ◽  
pp. 963-975 ◽  
Author(s):  
J. G. Casey ◽  
H. L. Pratt Jr. ◽  
C. E. Stillwell
Keyword(s):  
North Atlantic ◽  
Fork Length ◽  
Age And Growth ◽  
Adult Size ◽  
Von Bertalanffy ◽  
Frequency Data ◽  
Sandbar Shark ◽  
Length Frequency ◽  
Carcharhinus Plumbeus ◽  
Length Frequency Data

Age and growth of the sandbar shark (Carcharhinus plumbeus) was determined from rings in the vertebrae of 475 individuals, tagging data from 220 sharks at liberty for up to 17 yr, and length–frequency data from 2594 individuals. The oldest male sandbar aged in this study was 15 yr old and 154 cm fork length (FL); the oldest female was 21 yr old and 204 cm FL. The sexes grew at similar rates, 5.2–7.3 cm/yr. Females reached a larger adult size. Age to maturity was estimated at 13 yr in males and 12 yr in females. Tag returns indicated that sandbar sharks may live for over 30 yr. von Bertalanffy parameters for males are L∞ = 257, K = 0.0501, t0 = −4.5 and for females are L∞ = 299, K = 0.040, t0 = −4.9.

The impact of maternal protein restriction during perinatal life on the response to a septic insult in adult rats

2020 ◽  
pp. 1-8
Author(s):  
Reza Khazaee ◽  
Anastasiya Vinokurtseva ◽  
Lynda A. McCaig ◽  
Cory Yamashita ◽  
Daniel B. Hardy ◽  
...  
Keyword(s):  
Control Diet ◽  
Protein Restriction ◽  
Saline Control ◽  
Female Adult ◽  
Adult Rats ◽  
Male And Female ◽  
Maternal Protein Restriction ◽  
And Control ◽  
The Impact ◽  
Septic Insult

Abstract Although abundant evidence exists that adverse events during pregnancy lead to chronic conditions, there is limited information on the impact of acute insults such as sepsis. This study tested the hypothesis that impaired fetal development leads to altered organ responses to a septic insult in both male and female adult offspring. Fetal growth restricted (FGR) rats were generated using a maternal protein-restricted diet. Male and female FGR and control diet rats were housed until 150–160 d of age when they were exposed either a saline (control) or a fecal slurry intraperitoneal (Sepsis) injection. After 6 h, livers and lungs were analyzed for inflammation and, additionally, the amounts and function of pulmonary surfactant were measured. The results showed increases in the steady-state mRNA levels of inflammatory cytokines in the liver in response to the septic insult in both males and females; these responses were not different between FGR and control diet groups. In the lungs, cytokines were not detectable in any of the experimental groups. A significant decrease in the relative amount of surfactant was observed in male FGR offspring, but this was not observed in control males or in female animals. Overall, it is concluded that FGR induced by maternal protein restriction does not impact liver and lung inflammatory response to sepsis in either male or female adult rats. An altered septic response in male FGR offspring with respect to surfactant may imply a contribution to lung dysfunction.

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

Ultrastructural and molecular characterization of Bacillidium vesiculoformis n. sp. (Microspora: Mrazekiidae) in the freshwater oligochaete Nais simplex (Oligochaeta: Naididae)

Parasitology ◽  
2004 ◽  
Vol 130 (1) ◽  
pp. 31-40 ◽  
Author(s):  
D. J. MORRIS ◽  
R. S. TERRY ◽  
K. B. FERGUSON ◽  
J. E. SMITH ◽  
A. ADAMS
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Infected Cell ◽  
Host Cell ◽  
Developmental Stages ◽  
Parasite Development ◽  
Adhesive Quality ◽  
Transmission Studies ◽  
A New Species

The development of a new species, Bacillidium vesiculoformis n. sp. (Microspora, Mrazekiidae), is described from the freshwater oligochaete Nais simplex (Oligochaeta, Naididae). Initial stages of parasite development consist of a monokaryotic merogony within a haemocyte of the intestinal blood sinus. The resulting hypertrophied haemocyte is attached to the chloragocytes of the sinus by fine cytoplasmic extensions with the sinus around the cell becoming greatly enlarged. The meronts within the haemocyte form diplokaryotic sporonts that undergo sporogenesis directly within the cytoplasm of the host cell. The infected cell becomes packed with spores and developmental stages, causing it dramatically to increase in size, eventually rupturing the oligochaete and cell. Sporogony appears to be disporoblastic. Released spores were observed to have an adhesive quality. Transmission studies conducted with mature spores failed to transmit the parasite horizontally although vertical transmission was observed. Phylogenetic analysis of the parasite demonstrated that B. vesiculoformis clustered with microsporidian parasites of bryozoa and two other microsporidians, Janacekia debaiseuxi and an unidentified Bacillidium sp.

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