Assisted breeding technology in the saltwater crocodile Crocodylus porosus: a review and look to the future

2021 ◽  
Author(s):  
Stephen D. Johnston ◽  
John Lever ◽  
Robby McLeod ◽  
Edward Qualischefski ◽  
Monica Madrigal-Valverde ◽  
...  
Keyword(s):  
Saltwater Crocodile ◽  
Breeding Technology ◽  
The Future ◽  
Crocodylus Porosus

The assessment of sperm DNA fragmentation in the saltwater crocodile (Crocodylus porosus)

2017 ◽  
Vol 29 (3) ◽  
pp. 630 ◽  
Author(s):  
S. D. Johnston ◽  
C. López-Fernández ◽  
F. Arroyo ◽  
J. L. Fernández ◽  
J. Gosálvez
Keyword(s):  
Dna Damage ◽  
Dna Fragmentation ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Fragmented Dna ◽  
Sperm Dna ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus ◽  
Dispersion Test ◽  
Sperm Nuclei

Herein we report a method of assessing DNA fragmentation in the saltwater crocodile using the sperm chromatin dispersion test (SCDt) after including frozen–thawed spermatozoa in a microgel (Halomax; Halotech DNA, Madrid, Spain). Following controlled protein depletion, which included a reducing agent, sperm nuclei with fragmented DNA showed a homogeneous and larger halo of chromatin dispersion with a corresponding reduced nucleoid core compared with sperm with non-fragmented DNA. The presence of DNA damage was confirmed directly by incorporation of modified nucleotides using in situ nick translation (ISNT) and indirectly by studying the correlation of the SCDt with the results of DNA damage visualisation using a two-tailed comet assay (r = 0.90; P = 0.037). Results of the SCDt immediately following thawing and after 5 h incubation at 37°C in order to induce a range of DNA damage revealed individual crocodile differences in both the baseline level of DNA damage and DNA longevity.

Standardized Reference Ideogram for Physical Mapping in the Saltwater Crocodile (Crocodylus porosus)

2009 ◽  
Vol 127 (2-4) ◽  
pp. 204-212 ◽  
Author(s):  
P. Dalzell ◽  
L.G. Miles ◽  
S.R. Isberg ◽  
T.C. Glenn ◽  
C. King ◽  
...  
Keyword(s):  
Physical Mapping ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus

Post-testicular sperm maturation in the saltwater crocodile Crocodylus porosus: assessing the temporal acquisition of sperm motility

2021 ◽  
Author(s):  
Brett Nixon ◽  
Amanda L. Anderson ◽  
Elizabeth G. Bromfield ◽  
Jacinta H. Martin ◽  
Shenae L. Cafe ◽  
...  
Keyword(s):  
Sperm Motility ◽  
Sperm Maturation ◽  
Testicular Sperm ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus

Problem crocodiles, Crocodylus porosus, at Nhulunbuy, Northern Territory: an assessment of relocation as a mangaement strategy

1993 ◽  
Vol 20 (1) ◽  
pp. 127 ◽  
Author(s):  
B Walsh ◽  
PJ Whitehead
Keyword(s):  
Carrying Capacity ◽  
Northern Territory ◽  
Effective Strategy ◽  
Wet Season ◽  
Rates Of Return ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus ◽  
Remote Sites ◽  
Total Capture ◽  
Capture Rates

Since 1986 the Conservation Commission of the Northern Territory has operated a programme to remove 'problem' saltwater crocodiles from waters in and adjoining the township of Nhulunbuy. Over a period of five years, 52 different saltwater crocodiles (44 male) were captured. Most (48) were released at remote sites designated by the traditional Aboriginal owners of the surrounding lands. Release distances from the township varied from 17 to 282 km (by coastline). Many crocodiles (47.9%), including those released at the most distant sites, returned to, and were subsequently recaptured at, the township. Total capture rates (initial captures and recaptures pooled) varied seasonally, with fewer crocodiles being caught in the cooler dry season. During the wet season capture rates remained high, but relatively fewer 'new' crocodiles were caught. Probability of recapture could not be related to distance and direction of release from the township, nor size and sex of the released crocodile. Frequency of capture of individual crocodiles (1-8 times) was also unrelated to these variables. The high rates of return indicate that relocation is unlikely to be an effective strategy for managing humancrocodile interactions, at least in areas where potential release sites already support saltwater crocodile populations near carrying capacity.

Feeding Regime and Management of Captive Saltwater Crocodile, Crocodylus Porosus in Kota Tinggi, Johor

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Mohd Faudzir Najmuddin ◽  
◽  
Siti Hasmaliza Hassem ◽  
Nurhizatul Safikah Mohd Hauri ◽  
Fatin Zahari ◽  
...  
Keyword(s):  
Management Practices ◽  
Management Practice ◽  
Future Research ◽  
Captive Population ◽  
Feeding Frequency ◽  
Leather Industry ◽  
Feeding Regime ◽  
Saltwater Crocodile ◽  
In Captivity ◽  
Crocodylus Porosus

Crocodylus porosus is the largest species of crocodile and can be found in estuarine and riverine area in Malaysia. Crocodile in captivity can be found in Malaysia for various purposes such as tourism, conservation and leather industry. However, the management practice in established crocodile farm varies across park for example in terms of feeding regime. Thus, this study focusses on the feeding regime of C. porosus in captivity and evaluation of management of crocodile of Teluk Sengat Crocodile Farm. This study was carried out for 35 days in two different ponds of Teluk Sengat Crocodile Farm, Kota Tinggi, Johor. The results show majority of the food given to crocodile were chicken (64%), followed by fish (28%) and prawn (8%). Prawn was only given to juvenile crocodile every day, while fish and whole chicken were given to adult crocodile once a week. The feeding frequency are adequate for the juvenile crocodile however, the feeding quantity for adult pond are worrying. Future research should be conducted on other captive population of C. porosus in other areas in Malaysia as well to better understand the overall management practices in Malaysia.

scholarly journals Research Status on Suaeda heteroptera Kitag

2015 ◽  
Vol 3 (2) ◽  
pp. 23 ◽  
Author(s):  
Jing Ji
Keyword(s):  
Salt Tolerance ◽  
Morphological Characteristics ◽  
Biological Characteristics ◽  
Development Prospect ◽  
Research Status ◽  
Breeding Technology ◽  
The Future

<p><span style="font-family: Times New Roman;">The utilization value, morphological characteristics, biological characteristics, mechanism of salt tolerance, soil-repairing function, </span><span style="font-family: Times New Roman;">degradation, planting and breeding technology, </span><span style="font-family: Times New Roman;">development prospect and significance of <em>Suaeda heteroptera</em> Kitag were described, and the attentions which should be paid in its study and utilization in the future were put forward.</span></p>

scholarly journals A High-Quality Reference Genome Assembly of the Saltwater Crocodile, Crocodylus porosus, Reveals Patterns of Selection in Crocodylidae

2019 ◽  
Vol 12 (1) ◽  
pp. 3635-3646 ◽  
Author(s):  
Arnab Ghosh ◽  
Matthew G Johnson ◽  
Austin B Osmanski ◽  
Swarnali Louha ◽  
Natalia J Bayona-Vásquez ◽  
...  
Keyword(s):  
Genome Assembly ◽  
De Novo ◽  
Genome Structure ◽  
Protein Domain ◽  
Alligator Mississippiensis ◽  
Structure Evolution ◽  
Functional Protein ◽  
High Quality ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus

Abstract Crocodilians are an economically, culturally, and biologically important group. To improve researchers’ ability to study genome structure, evolution, and gene regulation in the clade, we generated a high-quality de novo genome assembly of the saltwater crocodile, Crocodylus porosus, from Illumina short read data from genomic libraries and in vitro proximity-ligation libraries. The assembled genome is 2,123.5 Mb, with N50 scaffold size of 17.7 Mb and N90 scaffold size of 3.8 Mb. We then annotated this new assembly, increasing the number of annotated genes by 74%. In total, 96% of 23,242 annotated genes were associated with a functional protein domain. Furthermore, multiple noncoding functional regions and mappable genetic markers were identified. Upon analysis and overlapping the results of branch length estimation and site selection tests for detecting potential selection, we found 16 putative genes under positive selection in crocodilians, 10 in C. porosus and 6 in Alligator mississippiensis. The annotated C. porosus genome will serve as an important platform for osmoregulatory, physiological, and sex determination studies, as well as an important reference in investigating the phylogenetic relationships of crocodilians, birds, and other tetrapods.

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