Slow life-history traits of a neritic predator, the bronze whaler (Carcharhinus brachyurus)

2017 ◽  
Vol 68 (3) ◽  
pp. 461 ◽  
Author(s):  
Michael Drew ◽  
Paul Rogers ◽  
Charlie Huveneers
Keyword(s):  
Life History ◽  
Growth Parameters ◽  
Isolated Populations ◽  
Life History Characteristics ◽  
Regional Estimates ◽  
Males And Females ◽  
Size At Age ◽  
Slow Growing ◽  
Best Fit ◽  
Age Estimates

Intra-species plasticity in the life-history characteristics of sharks leads to the need for regional estimates to accurately determine resilience to anthropogenic effects. The present study provides the first length-at-age, growth and maturity estimates for the bronze whaler (Carcharhinus brachyurus) from southern Australia. Age estimates were obtained from vertebral sections of 466 individuals spanning 50–308-cm total length. Maximum estimates of age for males and females were 25 and 31 years respectively. The three-parameter logistic model for females (L∞=308cm LT, k=0.15, α=742) and for males (L∞=317cm LT, k=0.13, α=782) provided the best fit to the size at age data. Males matured at a similar age (16 years), but smaller size than females (224v. 270cm LT). Growth parameters and age-at-maturity estimates were similar to those for genetically isolated C. brachyurus populations, and the sympatric dusky shark (C. obscurus). The southern Australian C. brachyurus population is long-lived, slow growing and late maturing. These growth parameters are needed to undertake demographic analyses to assess the resilience of C. brachyurus to fishing, and provide an example of a wide-ranging elasmobranch with similar life-history characteristics across isolated populations.

scholarly journals Subterranean Invasion by Gapped Ringed Crayfish: Effectiveness of a Removal Effort and Barrier Installation

Diversity ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 3 ◽  
Author(s):  
Joshua Mouser ◽  
David Ashley ◽  
Tom Aley ◽  
Shannon Brewer
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Major Threat ◽  
Males And Females ◽  
Native Crayfish ◽  
Age Estimates

Non-native crayfish invasion is a major threat to many stream fauna; however, invasions in subterranean habitats are rarely documented. Our study objectives were to examine demographics and morphological and life-history traits of a gapped ringed crayfish Faxonius neglectus chaenodactylus population that invaded Tumbling Creek Cave and determine the effects of removal on the population. Crayfish were found throughout the cave though fewer individuals were observed upstream of an installed weir. Fecund females were collected in nearly all months, but were prevalent during spring (February–June). Males and females were of similar sizes. Males had larger chelae and chelae that were regenerated slightly more often than females. Removal of >4000 crayfish since 2011 resulted in reduced abundances, but the population persisted. Age estimates from counting bands on gastric mills indicated crayfish within the cave lived longer than populations in nearby Big Creek (6 vs. 4 years). Recent efforts to prevent upstream cave migrations included a barrier installation and since installation, few crayfish have been located upstream. We show that exploitation of new environments may lead to trait changes (i.e., reproduction and longevity). We also demonstrate that barriers reduce the spread of invasion at a comparable cost to removal. We hypothesize that increased reservoir elevation inundates springs hydrologically connected to the cave and this may be the invasion source.

Life history parameters of the round sardinella Sardinella aurita in the Central East Atlantic off north-west Africa

2020 ◽  
Vol 100 (6) ◽  
pp. 997-1009
Author(s):  
Alba Jurado-Ruzafa ◽  
Eva Hernández ◽  
Verónica Duque-Nogal ◽  
Pedro J. Pascual-Alayón ◽  
M. Nazaret Carrasco ◽  
...  
Keyword(s):  
Life History ◽  
Growth Parameters ◽  
Biological Information ◽  
Change Scenario ◽  
African Countries ◽  
Precautionary Approach ◽  
North West ◽  
Males And Females ◽  
Sardinella Aurita ◽  
First Maturity

AbstractSardinella aurita has become an important source of fish protein-intake in NW African countries, where one stock is considered from Morocco to south Senegal, performing seasonal reproductive migrations along the coast. Although data are limited for the fisheries involved and for life-history knowledge of the species in the area, a precautionary approach is recommended to avoid overexploitation. Commercial landings of round sardinella produced by the European freezer-pelagic trawlers operating in Mauritanian waters were analysed between May 2004 and February 2012. The length-weight relationships (LWRs) (N = 40,725) did not show significant differences between sexes. Ripening round sardinellas were present throughout the year, but spawning effort rose between June and December. The length at first maturity for males and females was estimated at 27.7 cm TL (2.1 years) and 28.1 cm TL (2.2 years), respectively. Ages were interpreted from otoliths, varying from 0 to 8 years. Von Bertalanffy growth parameters resulted in non-statistically significant differences between sexes (P = 0.28). Natural mortality was estimated at ~0.63 year–1. The results provide important biological information for fisheries assessment of a species that plays an important key role in the current climate change scenario and for the economies of the riparian countries.

scholarly journals Using a simple morphometric marker to identify spatial units for abalone fishery management

2009 ◽  
Vol 66 (2) ◽  
pp. 305-314 ◽  
Author(s):  
T. Saunders ◽  
S. Mayfield ◽  
A. Hogg
Keyword(s):  
Life History ◽  
Fishery Management ◽  
Marine Invertebrates ◽  
Structured Populations ◽  
Systematic Sampling ◽  
Fine Scale ◽  
Isolated Populations ◽  
Current Management ◽  
Commercial Catch ◽  
Life History Characteristics

Abstract Saunders, T., Mayfield, S., and Hogg, A. 2009. Using a simple morphometric marker to identify spatial units for abalone fishery management. – ICES Journal of Marine Science, 66: 305–314. Managing stocks of sedentary marine invertebrates is complicated by the highly structured populations they form. Blacklip abalone (Haliotis rubra) form isolated populations with variable life-history characteristics. Many of the populations are “stunted”, attaining a lower maximum size than those in adjacent areas. To reduce the risks of overfishing and localized depletion, management units (MUs) that encompass individual populations need to be determined, then managed according to their life-history characteristics. Here, potential MUs in a South Australian abalone fishery were identified from the broad-scale, spatial distribution of stunted and “non-stunted” populations of blacklip abalone, by applying a morphometric marker to commercial shell samples. Key life-history parameters of the populations within the potential MUs were estimated using relationships between the morphometric marker and blacklip abalone biology. Data from fine-scale systematic sampling by commercial fishers were used to validate spatial patterns observed from the more broadly distributed commercial catch samples. The location, distribution, and size of potential MUs were largely inconsistent with those of current management. The locations of two MUs (in Gerloffs Bay) were consistent across the broad- and fine-scale datasets, with the fine-scale samples more informative for identifying a potential boundary between them. The disparity between these data and current management arrangements are highlighted, and approaches for modifying them are discussed. This approach is among the first to provide a practical means of more closely aligning the scales of assessment and management with biological reality for sedentary marine invertebrates.

The use of caudal thorns for ageing Raja undulata from the Portuguese continental shelf, with comments on its reproductive cycle

2007 ◽  
Vol 58 (11) ◽  
pp. 983 ◽  
Author(s):  
Teresa Moura ◽  
Ivone Figueiredo ◽  
Inês Farias ◽  
Bárbara Serra-Pereira ◽  
Rui Coelho ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Growth Parameters ◽  
Growth Models ◽  
Geographical Area ◽  
Growth Function ◽  
Age And Growth ◽  
Reproductive Analysis ◽  
First Maturity ◽  
Size At Age ◽  
Best Fit

The present study focuses on age estimation, with reproductive information contributing to the better understanding of the growth and the biology of Raja undulata. In the age and growth study, two calcified structures were used: caudal thorns and central vertebra. Results of readings showed that there were no significant differences in age estimates between the two structures. Both von Bertalanffy and Gompertz growth models were fitted to size-at-age data by sex and geographical area. No significant differences were found between sexes for the two models but significant differences were found between geographical areas (P = 0.05). The Gompertz growth function was selected as the best model to describe R. undulata growth because it presented the best fit and the most reasonable biological estimates. Reproductive analysis indicates one annual breeding season for R. undulata. The differences found in the estimates of length at first maturity between geographical areas (TL50% = 838 mm in Peniche and 762 mm in Algarve for females and TL50% = 781 mm in Peniche and 736 mm in Algarve for males), together with the regional differences found between growth parameters estimates (P = 0.05), may reflect the existence of different local populations of R. undulata on the Portuguese continental shelf.

Growth and longevity of Hawaiian grouper (Hyporthodus quernus) — input for management and conservation of a large, slow-growing grouper

2019 ◽  
Vol 76 (10) ◽  
pp. 1874-1884 ◽  
Author(s):  
Allen H. Andrews ◽  
Edward E. DeMartini ◽  
Jon Brodziak ◽  
Ryan S. Nichols ◽  
Robert L. Humphreys
Keyword(s):  
Life History ◽  
Conservation Status ◽  
Large Species ◽  
Life History Parameters ◽  
Fundamental Information ◽  
Hawaiian Grouper ◽  
Conservation Assessments ◽  
Slow Growing ◽  
Management And Conservation ◽  
Age Estimates

Hawaiian grouper (Hyporthodus quernus) is endemic to the Hawaiian Islands and is regionally important, yet little is known about its life history. This large species is managed within the Deep 7 bottomfish complex, which includes six snapper species that are assumed to have similar life history traits. Previous age estimates were not validated and suggested a maximum age of 34 years. To evaluate the preliminary study and provide a valid basis for life history parameters, we aged otoliths using bomb radiocarbon (14C) dating. Measured 14C values provided ages for smallest to largest fish that differed from the original study. The fundamental information provided here when evaluating Hawaiian grouper conservation status is longevity (valid to 50 years and estimated to 76 years) — no male sampled was <80 cm total length (TL) and younger than 34 years — and age-at-sexual maturity and age-at-sex change, which were indirectly estimated and compared with prior published estimates for this and other groupers. Updated life history parameters (k = 0.078, L∞ = 95.8 cm TL) should be used to improve future management and conservation assessments.

Ecology of isolated open-formation Tropidurus (Reptilia: Tropiduridae) in Amazonian lowland rain forest

1993 ◽  
Vol 71 (12) ◽  
pp. 2370-2390 ◽  
Author(s):  
Laurie J. Vitt
Keyword(s):  
Life History ◽  
Tropical Forest ◽  
Clutch Size ◽  
Northeastern Brazil ◽  
Close Relative ◽  
Isolated Populations ◽  
Rock Outcrops ◽  
Lowland Tropical Forest ◽  
Life History Characteristics ◽  
Clutch Mass

Ecological, morphological, and life-history characteristics of three as yet undescribed populations of open-formation Tropidurus species in Rondônia and a population of Tropidurus oreadicus in Pará, Brazil, that are isolated on rock outcrops completely surrounded by lowland tropical forest were compared with similar characteristics of a eurytopic open-formation close relative, Tropidurus hispidus, and a crevice-adapted close relative, Tropidurus semitaeniatus, from an open-formation (caatinga) habitat in northeastern Brazil. Individuals of the isolated Amazonian populations do not enter the forest, but escape into narrow crevices on rock outcrops when disturbed. They are restricted to the only habitat patch in tropical forest similar to open-formation habitats, granitic rock outcrops. The outcrops maintain cerrado and caatinga vegetation and published paleoecological data indicate that the forested area surrounding the outcrops in Rondônia was cerrado in the recent past. Individuals in the isolated Tropidurus populations are morphologically flattened compared with T. hispidis, clutch size is reduced, and relative clutch mass is reduced, as is observed in other crevice-adapted species of lizards. Females deposit eggs under granitic cap rocks, like the flattened lizard T. semitaeniatus. The most parsimonious explanation for the set of characteristics shared by these four isolated lizard populations is that natural selection has led to an adjustment of behavior, morphology, and certain life-history characteristics in response to the high ecological risks associated with entering surrounding forest. It remains unclear whether this occurred once (which assumes a common ancestor), followed by canalizing selection, or the populations converged independently on similar morphology and ecology (which assumes different ancestors). The direction of divergence in behavior, morphology, clutch size, relative clutch mass, and nesting behavior in isolated populations of Tropidurus species remains unknown.

Size-At-Age Variability and Sexual Dimorphism of Morphometric Characteristics in the Late Ontogenesis of the Marsh Frog, Pelophylax Ridibundus (Anura, Ranidae), from Terrytory of Crimea

2019 ◽  
Vol 53 (4) ◽  
pp. 325-334
Author(s):  
V. N. Peskov ◽  
N. A. Petrenko ◽  
V. Yu. Reminnyi
Keyword(s):  
Age Groups ◽  
The Body ◽  
Adult Males ◽  
Morphometric Characteristics ◽  
Morphometric Characters ◽  
Mean Values ◽  
Marsh Frog ◽  
Males And Females ◽  
Size At Age ◽  
Linear Body

Abstract We study size-at-age and sexual variability of morphometric characteristics of the marsh frog. According to the size of the body, males were divided into three size-age groups (juvenis, subadultus, adultus), females — into four groups (juvenis, subadultus, adultus, adultus-I). We found that the chronological age of frogs (skeletochronology) does not always correspond to their biological age (size and proportions of the body). We noted that the semi-adult males are reliably larger than females by mean values of 26 studied morphometric characters. Males and females of “adultus” group do not differ by linear body size, significant differences were found in body proportions (7 characters). For the females of “adultus-I” group, the mean values of 26 characters are significantly larger than for “adultus” males. The results of our study showed that with the age of the marsh frog, the level of exhibition, directionality and structure of morphometric sex differences changes.

Life History Traits in a Population of Pelobates syriacus (Boettger, 1889) from Turkey

2020 ◽  
Vol 27 (4) ◽  
pp. 195-200
Author(s):  
Ufuk Bülbül ◽  
Halime Koç ◽  
Yasemin Odabaş ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
...  
Keyword(s):  
Life History ◽  
Age Structure ◽  
Life History Traits ◽  
Spadefoot Toad ◽  
Males And Females

Age structure of the eastern spadefoot toad, Pelobates syriacus from the Kızılırmak Delta (Turkey) were assessed using phalangeal skeletochronology. Snout-vent length (SVL) ranged from 42.05 to 86.63 mm in males and 34.03 to 53.27 mm in females. Age of adults ranged from 2 to 8 years in males and 3 to 5 years in females. For both sexes, SVL was significantly correlated with age. Males and females of the toads reached maturity at 2 years of age.

scholarly journals Breast meat quality in males and females of fast-, medium- and slow-growing chickens fed diets of 2 protein levels

2021 ◽  
Vol 100 (4) ◽  
pp. 100997
Author(s):  
D. Chodová ◽  
E. Tůmová ◽  
M. Ketta ◽  
V. Skřivanová
Keyword(s):  
Meat Quality ◽  
Breast Meat ◽  
Protein Levels ◽  
Males And Females ◽  
Slow Growing

scholarly journals Physiological, Biochemical, and Growth Parameters of Fogera Cattle Calves to Heat Stress during Different Seasons in Sub-Humid Part of Ethiopia

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1062
Author(s):  
Michael Abera ◽  
Yesihak Yusuf Mummed ◽  
Mitiku Eshetu ◽  
Fabio Pilla ◽  
Zewdu Wondifraw
Keyword(s):  
Heat Stress ◽  
Growth Parameters ◽  
Hematological Parameters ◽  
Average Temperature ◽  
High Weight Gain ◽  
Different Seasons ◽  
Current Production ◽  
Humidity Index ◽  
Males And Females ◽  
Number Of Males

Fogera cattle are among indigenous breeds of cattle in the northern part of Ethiopia. However, their response to heat stress (HS) under different seasonal variations has not been well investigated. This study was aimed to determine physiological, hematological, biochemical, and growth parameters of Fogera cattle calves to HS during dry season, short rainy, and long rainy. A total of 72 calves (24 for each season) that were 6 months of age with an equal number of males and females were evaluated for physiological, hematological, biochemical, and growth parameters. Daily ambient temperature (AT) and relative humidity (RH) were recorded two times per day during the study periods from which the daily average temperature–humidity index (THI) was calculated. The study revealed higher AT and THI during dry and short seasons while higher RH was observed during the long rainy season. Physiological parameters except rectal temperature were affected by the seasons. Hematological parameters were also affected by season except for packed cell volume. Biochemical and growth parameters were also significantly affected by the seasons. THI was positively related with physiological but negatively with growth parameters. Thus, the THI value of 66 can be considered as optimum for high weight gain and normal physiological response to HS in Fogera cattle calves under their current production system.

Sign in / Sign up

Export Citation Format

Share Document