scholarly journals Aspects of the reproductive biology of the shortfin mako, Isurus oxyrinchus (Elasmobranchii Lamnidae), in the Southeastern region of Brazil

2002 ◽  
Vol 62 (2) ◽  
pp. 239-248 ◽  
Author(s):  
F. E. S. COSTA ◽  
F. M. S. BRAGA ◽  
C. A. ARFELLI ◽  
A. F. AMORIM
Keyword(s):  
Reproductive Biology ◽  
Tooth Replacement ◽  
Pregnant Females ◽  
Total Length ◽  
Isurus Oxyrinchus ◽  
Shortfin Mako ◽  
Inner Organs ◽  
Near Term ◽  
Southeastern Region

Uteri from four pregnant females and two newborn of shortfin mako, Isurus oxyrinchus, were collected in the southeastern region of Brazil, during September, October, and November of 1993 and 1994. All embryos were near-term with developing dentition and inner organs. Total length ranged from 64.5 to 72.0 cm, and the maximum number of embryos observed in a litter was 20. These observations further confirmed oophagy as a form of nutrition in this species, and its periodicity. The presence of teeth in the embryos' stomachs suggest that tooth replacement begins in the uterine phase.

scholarly journals Reproductive biology of the Brazilian blind electric ray Benthobatis kreffti (Chondrichthyes: Narcinidae)

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Mariana F. Martins ◽  
Otto B. F. Gadig
Keyword(s):  
Reproductive Biology ◽  
Southeastern Brazil ◽  
Natural Death ◽  
Total Length ◽  
Large Size ◽  
Female Total ◽  
Elasmobranch Species ◽  
Late Maturity ◽  
Near Term ◽  
Size At Birth

ABSTRACT This study provides information on the reproductive biology of the Brazilian blind electric ray Benthobatis kreffti, endemic to southern and southeastern Brazil. Individuals were caught by bottom trawl carried out in 2003 and 2007, at 492-501 m depth off the São Paulo State continental slope. A total of 152 females (115-299 mm) and 144 males (91-243 mm) were sampled. Maturity was first observed at 177 and 162 mm, with total length at 50% maturity of 191 and 176 mm in females and males respectively. Uterine fecundity ranged from 1-3 and was not related to female total length. Size at birth estimated from the largest near-term observed embryos and smallest free-swimming ray was 91-100 mm. The low fecundity observed is typical of deepwater elasmobranch species, as well as late maturity in comparison with costal species. The relatively large size-at-birth suggests that this species invests more in length of each embryo than in litter size, increasing the offspring’s survival chance. In this context, these parameters highlight the vulnerability of this and other deepwater species to non-natural death, mostly caused by deep-sea fisheries.

Occurrence of shortfin mako shark, Isurus oxyrinchus Rafinesque, 1810, off Turkey's coast

2015 ◽  
Vol 8 ◽  
Author(s):  
Hakan Kabasakal
Keyword(s):  
Aegean Sea ◽  
Seasonal Occurrence ◽  
Free Swimming ◽  
Mako Shark ◽  
New Born ◽  
Total Length ◽  
Isurus Oxyrinchus ◽  
Shortfin Mako ◽  
Northern Aegean Sea ◽  
New Evidence

Review of the available literature and the results of the present study revealed that 17 specimens ofIsurus oxyrinchuswere caught between 1950 and 2013. Nine (52.9%) of these verified 17 catches were recorded after 2000. Catches ofI. oxyrinchusoff Turkey's coast include specimens ranging from new-borns (65 cm total length) to huge adults (585 cm total length). A new-born female caught off the coast of Foça on 19 May 2015 represents the smallest free-swimming specimen ofI. oxyrinchusever recorded in Turkish waters. The occurrence of a new-born shortfin mako shark off Foça's coast provides new evidence to support the possibility of a mating region of lamniform sharks, includingI. oxyrinchus, in the northern Aegean Sea. The seasonal occurrence of both young and adult shortfin mako sharks off Turkey's Aegean and Mediterranean coasts should be monitored to clarify whether the shortfin mako shark is a resident or a vagrant species along the aforementioned coastline.

Growth and spatiotemporal distribution of juvenile shortfin mako (Isurus oxyrinchus) in the western and central North Pacific

2015 ◽  
Vol 66 (12) ◽  
pp. 1176 ◽  
Author(s):  
M. Kai ◽  
K. Shiozaki ◽  
S. Ohshimo ◽  
K. Yokawa
Keyword(s):  
North Pacific ◽  
Linear Models ◽  
North Pacific Ocean ◽  
Age Groups ◽  
Growth Curves ◽  
Growth Function ◽  
Gaussian Mixture ◽  
Isurus Oxyrinchus ◽  
Shortfin Mako ◽  
Central North Pacific

This paper presents an estimation of growth curves and spatiotemporal distributions of juvenile shortfin mako shark (Isurus oxyrinchus) in the western and central North Pacific Ocean using port sampling data collected from 2005 to 2013. The monthly length compositions show a clear transition of three modes in the size range of smaller than 150-cm precaudal length (PCL), which were believed to represent the growth of age-0 to age-2 classes, and they were then decomposed into age groups by fitting a Gaussian mixture distribution. Simulation data of lengths at monthly ages were generated from the mean and standard deviation of each distribution, and fit with a von Bertalanffy growth function. Parameters of the estimated growth curves for males and females were 274.4 and 239.4cm PCL for the asymptotic length and 0.19 and 0.25 year–1 for the growth coefficient indicating apparently faster growth than previously reported. Generalised linear models were applied to age-0 to explore the seasonal changes of PCL by area. They were born during late autumn and winter off the coast of north-eastern Japan, an area known to have relatively high productivity compared with other pelagic areas, and gradually expanded their habitat eastward and northward with the seasons as they grew.

Age and growth of the shortfin mako (Isurus oxyrinchus) in the south-eastern Pacific off Chile

2009 ◽  
Vol 60 (5) ◽  
pp. 394 ◽  
Author(s):  
Francisco Cerna ◽  
Roberto Licandeo
Keyword(s):  
Growth Parameters ◽  
Eastern Pacific ◽  
Age And Growth ◽  
The South ◽  
Age Classes ◽  
Vertebral Centra ◽  
South Eastern ◽  
Isurus Oxyrinchus ◽  
Shortfin Mako ◽  
Longline Fisheries

The shortfin mako, Isurus oxyrinchus, is a large pelagic shark with a widespread global distribution. However, very little is known about most aspects of this species for the south-eastern Pacific. In the present paper, the age and growth parameters of the shortfin mako, caught by Chilean swordfish longline fisheries from 2004 to 2005, are reported. Ages were estimated by counting band-pairs from sections of vertebral centra from 547 individuals, ranging from 76 to 330 cm in total length (TL). Trends in the proportion of opaque edges for all ages combined and grouped into ages 0–6 and 7–26 years indicated that they are formed during summer and showed that annually, one band-pair is formed in the vertebrae of shortfin makos. Modal-progression analysis was used to verify the first three age classes (ages 0–2 years). For both sexes, the oldest estimated age was 25+ years. Von Bertalanffy growth parameters were estimated at L∞ = 325.29 cm TL, K = 0.076 year–1 and t0 = –3.18 years for females and L∞ = 296.60 cm TL, K = 0.087 year–1 and t0 = –3.58 years for males. The results indicated that this species is highly vulnerable to exploitation and, thus, urgent conservation measures are required.

scholarly journals Reproductive biology of Artibeus fimbriatus Gray 1838 (Chiroptera) at the southern limit of its geographic range

2016 ◽  
Vol 16 (4) ◽  
Author(s):  
Camila S. Lima ◽  
Marta Elena Fabián
Keyword(s):  
Reproductive Biology ◽  
High Temperatures ◽  
Rainy Season ◽  
Regional Climate ◽  
Geographic Range ◽  
Reproductive Period ◽  
Southern Limit ◽  
Reproductive Patterns ◽  
Pregnant Females

Abstract Bats of the Phyllostomidae family exhibit different reproductive patterns in Neotropical regions and the strategy adopted depends on the regional climate. Here we studied the reproductive biology of Artibeus fimbriatus at the southern limit of their distribution in Brazil. This region has no rainy season, and the climate is characterized by high temperatures and variable photoperiods. We examined 129 A. fimbriatus females over several months, and used histological procedures where necessary in order to determine whether bats were pregnant. Females exhibited a long reproductive period and were pregnant from June until February. The reproduction events were found to be dependent on the photoperiod, but independent of annual accumulated precipitation. Our results show that at the southern limit of their distribution, A. fimbriatus exhibit seasonal-dependent reproductive patterns, with parturition events occurring during spring and summer, in which the days are longer and temperature is warmer.

In situ observation of stomach eversion in a line-caught Shortfin Mako (Isurus oxyrinchus)

2011 ◽  
Vol 109 (1) ◽  
pp. 212-216 ◽  
Author(s):  
Juerg M. Brunnschweiler ◽  
Frank Nielsen ◽  
Philip Motta
Keyword(s):  
In Situ Observation ◽  
Isurus Oxyrinchus ◽  
Shortfin Mako

scholarly journals Spatiotemporal variation in size-structured populations using fishery data: an application to shortfin mako (Isurus oxyrinchus) in the Pacific Ocean

2017 ◽  
Vol 74 (11) ◽  
pp. 1765-1780 ◽  
Author(s):  
Mikihiko Kai ◽  
James T. Thorson ◽  
Kevin R. Piner ◽  
Mark N. Maunder
Keyword(s):  
Coastal Waters ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Marine Species ◽  
Structured Populations ◽  
Spatiotemporal Model ◽  
The North ◽  
Isurus Oxyrinchus ◽  
Shortfin Mako ◽  
Catch Rates

We develop a length-disaggregated, spatiotemporal, delta-generalized linear mixed model (GLMM) and apply the method to fishery-dependent catch rates of shortfin mako sharks (Isurus oxyrinchus) in the North Pacific. The spatiotemporal model may provide an improvement over conventional time-series and spatially stratified models by yielding more precise and biologically interpretable estimates of abundance. Including length data may provide additional information to better understand life history and habitat partitioning for marine species. Nominal catch rates were standardized using a GLMM framework with spatiotemporal and length composition data. The best-fitting model showed that most hotspots for “immature” shortfin mako occurred in the coastal waters of Japan, while hotspots for “subadult and adult” occurred in the offshore or coastal waters of Japan. We also found that size-specific catch rates provide an indication that there has been a recent increasing trend in stock abundance since 2008.

scholarly journals Reproductive biology of Sympterygia bonapartii (Chondrichthyes: Rajiformes: Arhynchobatidae) in San Matías Gulf, Patagonia, Argentina

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
María L. Estalles ◽  
María R. Perier ◽  
Edgardo E. Di Giácomo
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Biology ◽  
Early Spring ◽  
Egg Laying ◽  
Reproductive Pattern ◽  
Reproductive Parameters ◽  
Egg Capsules ◽  
Northern Patagonia ◽  
Total Length

ABSTRACT This study estimates and analyses the reproductive parameters and cycle of Sympterygia bonapartii in San Matías Gulf, northern Patagonia, Argentina. A total of 827 males and 1,299 females were analysed. Males ranged from 185 to 687 mm of total length (TL) and females from 180 to 742 mm TL. Sexual dimorphism was detected; females were larger, heavier, exhibited heavier livers, wider discs and matured at lager sizes than males. Immature females ranged from 180 to 625 mm TL, maturing females from 408 to 720 mm TL, mature ones from 514 to 742 mm TL and females with egg capsules from 580 to 730 mm TL. Immature males ranged from 185 to 545 mm TL, maturing ones from 410 to 620 mm TL and mature males from 505 to 687 mm TL. Size at which 50% of the skates reached maturity was estimated to be 545 mm TL for males and 594 mm TL for females. According to the reproductive indexes analysed, S. bonapartii exhibited a seasonal reproductive pattern. Mating may occur during winter-early spring and the egg-laying season, during spring and summer.

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