Morphometric analysis of the Australian freshwater crocodile (Crocodylus johnstoni)

2017 ◽  
Vol 65 (2) ◽  
pp. 97 ◽  
Author(s):  
Glenn P. Edwards ◽  
Grahame J. Webb ◽  
S. Charlie Manolis ◽  
Alex Mazanov
Keyword(s):  
Morphometric Analysis ◽  
Body Measurements ◽  
Body Parts ◽  
Allometric Growth ◽  
Relative Growth ◽  
Crocodylus Johnstoni ◽  
Arnhem Land ◽  
Freshwater Crocodile ◽  
Crocodylus Porosus ◽  
Australian Freshwater

We conducted a morphometric analysis of 279 Crocodylus johnstoni, using specimens from the McKinlay River (n = 265) and Arnhem Land (n = 14), to meet the management need for predicting body size of C. johnstoni from isolated body parts. The results also allow reconstruction of C. johnstoni dimensions for comparison with other crocodilian species. We detected sexual dimorphism in some body measurements from the McKinlay River, and geographic variation in the morphology of McKinlay River and Arnhem Land populations, but differences were slight. There is pronounced allometric growth in C. johnstoni in the immediate post-hatching phase, largely due to elongation of the snout after exiting the confines of the egg. We compared the size, shape and relative growth of C. johnstoni with that of other crocodilian species for which equivalent data are available, but particularly the other Australian crocodile, Crocodylus porosus. C. porosus has a proportionately longer tail and a shorter but wider snout than C. johnstoni, and we discuss possible ecological correlates of these and other differences.

Remote monitoring of crocodilians: implantation, attachment and release methods for transmitters and data-loggers

2009 ◽  
Vol 60 (4) ◽  
pp. 284 ◽  
Author(s):  
Craig E. Franklin ◽  
Mark A. Read ◽  
Peter G. Kraft ◽  
Niko Liebsch ◽  
Steve R. Irwin ◽  
...  
Keyword(s):  
Physiological Variables ◽  
Crocodylus Johnstoni ◽  
Data Loggers ◽  
Archival Tags ◽  
Crocodylus Porosus ◽  
Electronic Tags ◽  
Free Ranging ◽  
Australian Freshwater ◽  
Term Management

Crocodilians are by their very nature difficult animals to study. However, research on wild animals is essential for the development of reliable long-term management. Here, we describe methods for the acquisition and monitoring of behavioural and physiological variables from free-ranging crocodilians through the use of archival tags (data-loggers) and via satellite, radio and acoustic telemetry. Specifically, the attachment or implantation of electronic tags is described and examples provided of the type of data that can be collected. Our research group has used a combination of approaches to monitor the movements, diving activity, body temperatures and heart rates of crocodilians, including studies on the Australian freshwater crocodile (Crocodylus johnstoni), the estuarine crocodile (Crocodylus porosus) and the caiman (Caiman latirostris). Each approach or method presents unique challenges and problems, chiefly as a consequence of differences in body morphology and size of the crocodilian species, their behaviours and the habitats they occupy.

Proctocaecum blairi sp. nov. (Digenea, Cryptogonimidae) from the freshwater crocodile, Crocodylus johnstoni, in Northern Territory, Australia

2010 ◽  
Vol 55 (3) ◽  
Author(s):  
Vasyl Tkach ◽  
Scott Snyder
Keyword(s):  
New Species ◽  
Relative Length ◽  
Anterior Testis ◽  
Northern Territory ◽  
The Body ◽  
Body Proportions ◽  
Diagnostic Features ◽  
Crocodylus Johnstoni ◽  
Freshwater Crocodile ◽  
Australian Freshwater

AbstractProctocaecum blairi sp. nov. is described from specimens found in the intestine of an Australian freshwater crocodile, Crocodylus johnstoni, from Northern Territory, Australia. The most important diagnostic features of the new species are the body proportions and size, the position of the pharynx (relative length of the prepharynx and oesophagus), the relative length and position of the vitelline fields, and the number, shape and size of the circumoral spines. The new species is morphologically most similar to Proctocaecum atae, P. elongatum, P. crocodili, P. gairhei and Acanthostomum slusarskii. It differs from all of these species in having a much longer prepharynx, and differs from both P. atae and P. crocodili in having a much longer body and posteriorly situated vitelline fields. Proctocaecum blairi sp. nov. differs from P. elongatum in having a shorter body, a greater forebody to hindbody ratio, a much smaller ventral sucker, and a higher number of circumoral spines (23 vs 21 in P. elongatum). The new species differs from P. gairhei in possessing a much larger body length:width ratio and an ovary separated from the anterior testis by a seminal receptacle. Acanthostomum slusarskii lacks a gonotyl and has fewer circumoral spines than the new species. Proctocaecum blairi sp. nov. is the third species of Proctocaecum and the fourth cryptogonimid species known from crocodiles in Australia.

scholarly journals Studies on the allometric growth of the caramote prawn Melicertus kerathurus (Decapoda, Penaeidae) in Western Greece (E. Mediterranean)

2009 ◽  
Vol 10 (1) ◽  
pp. 25 ◽  
Author(s):  
K. KAPIRIS ◽  
E. KALLIAS ◽  
A. CONIDES
Keyword(s):  
Carapace Length ◽  
Western Mediterranean ◽  
Body Parts ◽  
Allometric Growth ◽  
Metabolic Processes ◽  
Maximum Width ◽  
Relative Growth ◽  
Appendix Masculina ◽  
Males And Females ◽  
Western Greece

The relative growth of eleven body parts (carapace length, height, width, abdominal length, height and width, rostral length and telson length) of males and females of the caramote prawn Melicertus kerathurus was studied in samples from the Amvrakikos Gulf (Western Greece, E. Mediterranean). In addition to this, the relative growth of the length and the maximum width – and consequently the surface - of the appendix masculina of males was also studied. In general, both sexes showed similar patterns of relative growth. However, the females’ body appendages were significantly greater than those of the males. A negative allometry of escaping appendages (telson), abdomen (related to the metabolic processes, rapid locomotion and reproduction), rostrum, appendix masculina (related to mating and sperm transfer) and carapace height and width was found in both sexes. The biometric studies in this species in the central and western Mediterranean are in agreement with those from the eastern part of the basin, suggesting that all the populations throughout the Mediterranean could be considered as uniform.

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