VARIATION, SEXUAL DIMORPHISM, AND MATURITY IN A QUEBEC POPULATION OF THE COMMON SNAPPING TURTLE, CHELYDRA SERPENTINA

1960 ◽  
Vol 38 (1) ◽  
pp. 19-38 ◽  
Author(s):  
James E. Mosimann ◽  
J. Roger Bider
Keyword(s):  
Carapace Length ◽  
Relative Rate ◽  
Analysis Of Covariance ◽  
Head Width ◽  
Posterior Lobe ◽  
Chelydra Serpentina ◽  
Single Population ◽  
Species Analysis ◽  
The Common ◽  
Males And Females

An analysis was made of a sample of 55 snapping turtles, Chelydra serpentina, from a single locality in southern Quebec. The variation studied is regarded as being representative of that of a single population of the species. Analysis of covariance was used in studying dimorphism in various measurements. Conclusions reached are: (a) the sex ratio is one; (b) males grow to a larger size than females; (c) males and females become mature at a carapace length of about 200 millimeters; (d) the ratio precloacal distance over posterior lobe of the plastron gives a practical index for sex determination in adults; (e) there is a set of small but interrelated changes correlated with a greater precloacal distance in the male: These are that males have the plastron shifted forward slightly, have the bridge slightly longer relative to plastron length, and have the posterior lobe of the plastron slightly shorter relative to plastron length; (f) the precloacal length of the male (which area accommodates the penis) grows relatively faster than carapace length; the precloacal length of the female grows at the same relative rate as carapace length; (g) there is virtually no dimorphism in shell dimensions nor in head width.

scholarly journals A multivariate study of variation in two species of rock crab of the genus Leptograpsus

1974 ◽  
Vol 22 (3) ◽  
pp. 417 ◽  
Author(s):  
NA Campbell ◽  
RJ Mahon
Keyword(s):  
Carapace Length ◽  
Carapace Width ◽  
The Body ◽  
Canonical Variate ◽  
Multivariate Approach ◽  
Maximum Width ◽  
Multivariate Study ◽  
Rock Crab ◽  
Males And Females ◽  
Colour Form

A multivariate approach has been used to study morphological variation in the blue and orange-form species of rock crab of the genus Leptograpsus. Objective criteria for the identification of the two species are established, based on the following characters: width of the frontal region of the carapace; width of the posterior region of the carapace (rear width); length of the carapace along the midline; maximum width of the carapace; and the depth of the body. The first canonical variate, which differentiates between the two species, represents a contrast between the carapace width relative to the width of the front lip and the depth of the body; the blue-form species has a greater relative carapace width than has the orange form. The second canonical variate, which presents a contrast between the rear width and the carapace length, identifies males and females within each species; males have a greater relative carapace length than have females. All individuals, including 20 not used in the study, were correctly identified for colour form. The clear separation of the blue and orange forms achieved by canonical analysis supports the previously determined specific status of the two forms.

scholarly journals New size record for Snapping Turtle (Chelydra serpentina) in southern Quebec, Canada

2019 ◽  
Vol 132 (4) ◽  
pp. 378-381
Author(s):  
Patrick Galois ◽  
Ève-Lyne Grenier ◽  
Martin Ouellet
Keyword(s):  
Population Structure ◽  
Adult Male ◽  
General Condition ◽  
Carapace Length ◽  
Maximum Size ◽  
Chelydra Serpentina ◽  
Snapping Turtle ◽  
Good General Condition ◽  
Turtle Population ◽  
Local Habitat

We report a new size record for a Snapping Turtle (Chelydra serpentina) in Quebec, Canada. We captured an adult male in good general condition in the Rivière du Sud in the southern Montérégie region. Its straight midline carapace length was 43.2 cm (maximum carapace length 45.1 cm), and it weighed 19.8 kg. This record contributes to our understanding of the maximum size of this species at the northeastern part of its range. More intensive effort will be necessary to document the Snapping Turtle population structure in Quebec to allow for sound comparisons with other populations, as well as a better understanding of the effects of elevation, latitude, and local habitat on Snapping Turtle growth and size.

Panulirus echinatus population in the Brazilian oceanic ecosystem Rocas Atoll

Crustaceana ◽  
2019 ◽  
Vol 92 (2) ◽  
pp. 221-232 ◽  
Author(s):  
Juliana Gaeta ◽  
Raúl Cruz
Keyword(s):  
Sex Ratio ◽  
Carapace Length ◽  
Reproduction Period ◽  
Males And Females ◽  
The Mean ◽  
Oceanic Ecosystem ◽  
Abundant Population ◽  
Future Information

Abstract In Rocas Atoll (03°51′S 033°48′W) a most abundant population of Panulirus echinatus Smith, 1869 was observed during free dives. Numbers of males and females were almost the same, with an overall sex ratio M : F = 1.1. In addition, males are larger than females, with a mean male carapace length (CL) of 92.6 ± 1.8 mm, while the female mean CL was 72.7 ± 1.0 mm and for both sex combined the mean CL was 83.1 ± 1.4 mm. The percentage of females breeding, i.e., with a spermatophore mass or eggs, was 75.1%. More information is needed to better understand the fluctuation in densities over a year cycle, the reproduction period, and differences in CL between males and females, as well as other aspects of the biology of this species. The present work and future information could help to formulate fisheries policies aimed at protecting P. echinatus stocks.

Conservation Genetics of the Common Snapping Turtle (Chelydra serpentina)

1996 ◽  
Vol 10 (2) ◽  
pp. 397-405 ◽  
Author(s):  
Christopher A. Phillips ◽  
Walter W. Dimmick ◽  
John L. Carr
Keyword(s):  
Conservation Genetics ◽  
Chelydra Serpentina ◽  
Snapping Turtle ◽  
The Common

scholarly journals Status, distribution, and nesting ecology of Snapping Turtle (Chelydra serpentina) on Cape Breton Island, Nova Scotia, Canada

2018 ◽  
Vol 132 (1) ◽  
pp. 8-17
Author(s):  
Terry Power ◽  
John Gilhen
Keyword(s):  
Carapace Length ◽  
Current Knowledge ◽  
Average Rate ◽  
Carapace Width ◽  
Chelydra Serpentina ◽  
Eastern Canada ◽  
Nesting Ecology ◽  
Cape Breton Island ◽  
Snapping Turtle ◽  
Cape Breton

Based on current knowledge of the ecology and distribution of Snapping Turtle (Chelydra serpentina), both in eastern Canada and elsewhere, we conclude this species is native to Cape Breton Island. Seventy-two reports of Snapping Turtle from Cape Breton (1999–2017) indicate a range centred in the area south of Bras d’Or Lake. Date of oviposition ranged from 19 June to 10 July (median = 26 June) among 26 nests observed during 2012–2014. Clutch size for these nests was 23–65 eggs (mean = 46) and among 25 protected nests average rate of hatchling emergence was 21.5%. Time from oviposition to emergence of hatchlings (n = 256) was 75–120 days (mean = 87.2; SD = 9.0) among 20 nests. First emergence ranged from 9 September to 20 October (75–114 nest days; mean = 90) and last emergence ranged from 13 September to 28 October (86–120 nest days; mean = 100). Duration of emergence ranged from one day (i.e., synchronous emergence; five nests) to 37 days (mean = 11 days). The number of days on which hatchlings emerged at a nest ranged from one to nine days (mean = 4 days). Maximum carapace length was 25.0–31.8 mm (mean = 29.0 mm) and maximum carapace width was 23.5–30.0 mm (mean = 27.0 mm) for 256 hatchlings that emerged from 20 protected nests. Mass of hatchlings was 4.9–9.9 g (mean = 7.8 g).

The Diet of the Common Toad (Bufo bufo) around a Pond in Mid-Wales

1987 ◽  
Vol 8 (1) ◽  
pp. 13-17 ◽  
Author(s):  
S.P. Gittins
Keyword(s):  
Bufo Bufo ◽  
Adult Males ◽  
Common Toad ◽  
Food Items ◽  
Inorganic Matter ◽  
Significant Difference ◽  
The Common ◽  
Males And Females ◽  
Toad Bufo ◽  
Toad Bufo Bufo

AbstractThere was no significant difference between the number of food items obtained by stomach-flushing toads caught in pitfall traps and from the dissection of corpses found on nearby roads. The frequencies of the different food categories were similar using the two methods. 97 % of the toads entering the pond in the spring had not recently fed, whereas 25% of toads leaving the pond had started to feed. Sloughed skin was found in 7% of stomachs. Vegetable matter was found in 15% of stomachs and inorganic matter in 6% of stomachs. The diet of the toad was found to be very varied, and the main food items were beetles, collembolans, millipedes, harvestmen and spiders. The diets of males, females and young toads were very similar, and only slight changes in diet were observed throughout the year. The size of food items ranged from 1 mm to 40 mm with most around 7 mm. There was no significant relationship between the size of the food item and the size of the toad for adult males and females, but there was for juveniles.

Growth pattern and longevity of Parapenaeus fissuroides Crosnier, 1985 (Decapoda, Penaeidae) in Kagoshima Bay, southern Japan

Crustaceana ◽  
2017 ◽  
Vol 90 (2) ◽  
pp. 153-166 ◽  
Author(s):  
Zannatul Farhana ◽  
Jun Ohtomi
Keyword(s):  
Growth Pattern ◽  
Benthic Community ◽  
Carapace Length ◽  
Growth Equation ◽  
Age Group ◽  
Length Frequency ◽  
Frequency Distributions ◽  
Kagoshima Bay ◽  
Males And Females ◽  
Autumn And Winter

Parapenaeus fissuroidesCrosnier, 1985 is an emergent fisheries shrimp resource in the benthic community of Kagoshima Bay. The growth pattern and longevity ofP. fissuroideswere estimated from monthly length-frequency distributions. Carapace length (CL) ranged from 7.7-27.1 mm in males and 6.4-36.1 mm in females. Both males and females were recruited during late autumn and winter. Growth was best described by Pauly & Gaschütz’s growth equation as for males and for females. Females grew faster and reached larger sizes than males of the same age group. The life-span ofP. fissuroideswas estimated to be around 2 years for males and 2.5 years for females.

Hibernacula Use and Hibernation Phenology in the Common Snapping Turtle (Chelydra serpentina) in Canaan Valley, West Virginia

2012 ◽  
Vol 46 (2) ◽  
pp. 269-274 ◽  
Author(s):  
Gabriel F. Strain ◽  
James T. Anderson ◽  
Edwin D. Michael ◽  
Philip J. Turk
Keyword(s):  
West Virginia ◽  
Chelydra Serpentina ◽  
Snapping Turtle ◽  
The Common ◽  
Canaan Valley
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