Growth rates and body condition factors of Alligator mississippiensis in coastal Louisiana wetlands: A comparison of wild and farm-released juveniles

Elsey, Ruth M.; Joanen, Ted; McNease, Larry; Kinler, Noel

doi:10.1016/0300-9629(92)90164-l

Cited by 44 publications

(38 citation statements)

References 9 publications

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“…So, reintroduction occurs, when they almost attain size class II (Ross and Godshalk, 2003), at the same nest sites were the eggs were harvested. Reintroduced animals also present higher survivorship than wild animals of the same cohort, since survivorship in crocodilians is size related (Rootes, 1989;Elsey et al, 1992). These size differences between wild and reintroduced animals are expected to exist for a few years.…”

Section: Discussionmentioning

confidence: 99%

Size of nesting female Broad-snouted Caimans (Caiman latirostris Daudin 1802)

Leiva

Simoncini

Portelinha³

et al. 2019

Braz. J. Biol.

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The southern distribution of the Broad-snouted Caiman (Caiman latirostris Daudin 1802) in Argentina occurs in Santa Fe Province, where its population has been under management by "Proyecto Yacaré" since 1990. From 1997 to 2016, we captured 77 nesting female Broad-snouted Caimans in Santa Fe Province. Our results suggest that previously defined size classes for Broad-snouted Caiman do not adequately describe the reproductively mature female segment of the population. Here we propose to change size ranges for general size classes for Broad-snouted Caiman. In addition, we have observed that reintroduced reproductive females by Proyecto Yacaré represent about 32% of captured females. These results indicate that reintroduced females by the management program are surviving and reproducing in the wild at least up to 20 years.Keywords: management, size class, reproduction, sexual maturity. Tamanho de fêmeas nidificantes do jacaré-de-papo-amarelo (Caiman latirostris Daudin 1802)Resumo Na Argentina, a distribuição mais austral do jacaré-de-papo-amarelo (Caiman latirostris Daudin 1802) ocorre na Provincia de Santa Fe, sendo que suas populações são manejadas pelo "Proyecto Yacaré" desde 1990. Entre os anos de 1997 e 2016, nós capturamos 77 fêmeas nidificantes do jacaré-de-papo-amarelo em Santa Fe. Nossos resultados sugerem que as classes de tamanho definidas para o jacaré-de-papo-amarelo não representam a realidade dos animais capturados no presente estudo. Portanto, propõe-se uma alteração nas classes de tamanho para o jacaré-de-papo-amarelo. Nós também observamos que as fêmeas reintroduzidas pelo "Proyecto Yacaré" representaram 32% das fêmeas capturadas. Estes resultados indicam que fêmeas reintroduzidas pelo programa de manejo estão sobrevivendo e reproduzindo na natureza por, pelo menos, 20 anos.Palavras-chave: manejo, classe de tamanho, reprodução, maturidade sexual.

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Section: Discussionmentioning

confidence: 99%

Size of nesting female Broad-snouted Caimans (Caiman latirostris Daudin 1802)

Leiva

Simoncini

Portelinha³

et al. 2019

Braz. J. Biol.

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“…We did not know the age of these free-living animals, but alligator growth rates have been previously studied in coastal Louisiana wetlands (Chabreck and Joanen 1979, Elsey et al 1992, Rootes et al 1991. Growth rates of males and females do not differ significantly (≈ 36 cm/year) until about 3 years of age, when animals have reached about 1 m in length (Elsey et al 1992). Growth rate then appears to decline more rapidly in females than in males (Rootes et al 1991).…”

Section: Discussionmentioning

confidence: 99%

“…Blood cells typically have a high turnover rate (Chang andHarley 1995, Cline andWaldmann 1962), and thus, blood is an excellent candidate tissue for aging studies. We did not know the age of these free-living animals, but alligator growth rates have been previously studied in coastal Louisiana wetlands (Chabreck and Joanen 1979, Elsey et al 1992, Rootes et al 1991. Growth rates of males and females do not differ significantly (≈ 36 cm/year) until about 3 years of age, when animals have reached about 1 m in length (Elsey et al 1992).…”

Section: Discussionmentioning

confidence: 99%

Telomere Length Shortens with Body Length in Alligator mississippiensis

Scott

Haussmann

Elsey

et al. 2006

Southeastern Naturalist

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In Alligator mississippiensis (American Alligator), body length increases with age, but body length can be used as an accurate estimator of age only up to about 6-7 years, when growth rates slow considerably. Telomeres are repetitive DNA sequences that cap the ends of each chromosome. Telomeres shorten with age in most animals, but telomere shortening has not been examined in reptiles. We measured telomere length in erythrocytes of A. mississippiensis varying between ≈ 5 and 240 cm in body length and found a negative relationship between telomere length and body length (P < 0.01). Assuming that erythrocyte telomeres continue to shorten with time, even after growth rate declines, those individuals with the shortest telomeres should be the oldest members of the population. This method of estimating age, even in animals of similar body size, should allow questions about age structure and senescence to be addressed. RightsFurther reproduction or distribution, either in whole or in part, except for personal research purposes, is prohibited without the written consent of the publisher, Eagle Hill Institute.This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/eeob_las_pubs/17BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Telomere Length Shortens with Body Length in Alligator mississippiensisAuthor (s) Abstract -In Alligator mississippiensis (American Alligator), body length increases with age, but body length can be used as an accurate estimator of age only up to about 6-7 years, when growth rates slow considerably. Telomeres are repetitive DNA sequences that cap the ends of each chromosome. Telomeres shorten with age in most animals, but telomere shortening has not been examined in reptiles. We measured telomere length in erythrocytes of A. mississippiensis varying between ≈ 5 and 240 cm in body length and found a negative relationship between telomere length and body length (P < 0.01). Assuming that erythrocyte telomeres continue to shorten with time, even after growth rate declines, those individuals with the shortest telomeres should be the oldest members of the population. This method of estimating age, even in animals of similar body size, should allow questions about age structure and senescence to be addressed.

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“…insect (Lampert and Trubetskova, 1996); reptile (Sinervo and Adolph, 1989); mammal (Kraus et al, 2005); bird (Richner, 1989)]. Alligator growth can be highly variable, and dependent upon environment, life history and food availability (Coulson et al, 1973;Chabreck and Joanen, 1979;Jacobsen and Kushlan, 1989;Rootes et al, 1991;Elsey et al, 1992). For example, a population of wild, 1 year old alligators can weigh less than 0.5kg, whereas artificially high temperatures and unlimited access to food can allow pen-reared, 1 year old alligators to weigh 7kg (Coulson et al, 1973).…”

Section: Surgical Removal Of R-l Cardiac Shunt Does Not Greatly Affecmentioning

confidence: 99%

Turning crocodilian hearts into bird hearts: growth rates are similar for alligators with and without right-to-left cardiac shunt

Eme

Gwalthney

Owerkowicz

et al. 2010

Journal of Experimental Biology

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SUMMARYThe functional and possible adaptive significance of non-avian reptiles' dual aortic arch system and the ability of all non-avian reptiles to perform central vascular cardiac shunts have been of great interest to comparative physiologists. The unique cardiac anatomy of crocodilians -a four-chambered heart with the dual aortic arch system -allows for only right-to-left (R-L; pulmonary bypass) cardiac shunt and for surgical elimination of this shunt. Surgical removal of the R-L shunt, by occluding the left aorta (LAo) upstream and downstream of the foramen of Panizza, results in a crocodilian with an obligatory, avian/mammalian central circulation. In this study, R-L cardiac shunt was eliminated in age-matched, female American alligators (Alligator mississippiensis; 5-7 months of age). We tested the hypothesis that surgical elimination of R-L cardiac shunt would impair growth (a readily measured proxy for fitness) compared with sham-operated, age-matched controls, especially in animals subjected to exhaustive exercise. While regular exercise caused a decrease in size (snout-to-vent length, head length and body mass), elimination of the capacity for R-L cardiac shunt did not greatly reduce animal growth, despite a chronic ventricular enlargement in surgically altered juvenile alligators. We speculate that, despite being slightly smaller, alligators with an occluded LAo would have reached sexual maturity in the same breeding season as control alligators. This study suggests that crocodilian R-L cardiac shunt does not provide an adaptive advantage for juvenile alligator growth and supports the logic that cardiac shunts persist in crocodilians because they have not been selected against. Supplementary material available online at

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Growth rates and body condition factors of Alligator mississippiensis in coastal Louisiana wetlands: A comparison of wild and farm-released juveniles

Cited by 44 publications

References 9 publications

Size of nesting female Broad-snouted Caimans (Caiman latirostris Daudin 1802)

Size of nesting female Broad-snouted Caimans (Caiman latirostris Daudin 1802)

Telomere Length Shortens with Body Length in Alligator mississippiensis

Turning crocodilian hearts into bird hearts: growth rates are similar for alligators with and without right-to-left cardiac shunt

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