Growth Rates of Crocodylus Porosus (Reptilia: Crocodilia) From Arnhem Land, Northern Australia.

1978 ◽  
Vol 5 (3) ◽  
pp. 385 ◽  
Author(s):  
GJW Webb ◽  
H Messel ◽  
J Crawford ◽  
MJ Yerbury
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Growth Curve ◽  
Exponential Growth ◽  
Maximum Size ◽  
Northern Australia ◽  
Wet Season ◽  
Second Growth ◽  
Arnhem Land ◽  
Crocodylus Porosus

In C. porosus < 80 cm SVL (snout-vent length), growth rate decreases as body size increases; males grow faster than females, and both sexes grow faster in the wet season than in the dry season. If the exponential growth curve for specimens < 80cm SVL is extrapolated, it underestimates the maximum size of C. porosus. A second growth curve for specimens > 80cm SVL has been derived separately, and the two curves intersect in the vicinity of 70 cm SVL. The size at which C. porosus cease growing seems quite variable and some data indicate a range of 3.9-6.0 m total length for males. The twocurve growth model is thought to reflect an energetic advantage in feeding on large rather than small prey.

The Foods and Feeding Habits of Subadult Crocodylus Porosus Schneider in Northern Australia.

1979 ◽  
Vol 6 (3) ◽  
pp. 347 ◽  
Author(s):  
JA Taylor
Keyword(s):  
Feeding Habits ◽  
Stomach Contents ◽  
Northern Territory ◽  
Northern Australia ◽  
Wet Season ◽  
Flood Plains ◽  
Significant Difference ◽  
Arnhem Land ◽  
Crocodylus Porosus ◽  
Slow Moving

Stomach contents were studied for 289 live young crocodiles (Crocodylus porosus) less than 180 cm long, collected from coast, river and swamp of Arnhem Land, Melville Island and Grant Island, Northern Territory, Australia; the crocodiles were then released. Tables give orders and families and some generic and specific names for prey or carrion eaten and for 3 parasites on the crocodiles, for a dry and a wet season in 1975-76. Between crocodiles 50 to 120 cm long and those smaller or larger there was no significant difference in the proportion of crocodiles having eaten crabs, shrimps, fish or insects or with empty stomachs, but only the larger crocodiles ate mammals or birds. Frequency of different foods eaten differed significantly with type of habitat or with salinity. Weight of food or incidence of empty stomachs did not differ between seasons, habitats or salinities. Condition of the crocodiles was significantly poorer for those from freshwater swamps than for those from lower mangrove or flood plains, and highest for those from upper mangrove. Main foods in both seasons were crustaceans, mainly crabs of subfamily Sesarminae and shrimps of genus Macrobrachium. The only fish eaten regularly was Pseudogobius sp., a slow-moving fish found by the water's edge. Amphibians were not found in the stomach.

Morphometric analysis of Crocodylus porosus from the north coast of Arnhem Land, Northern Australia

1978 ◽  
Vol 26 (1) ◽  
pp. 1 ◽  
Author(s):  
. Webb.G.J.W ◽  
H Messel
Keyword(s):  
Body Size ◽  
Specific Problem ◽  
Maximum Size ◽  
The Body ◽  
Tissue Loss ◽  
North Coast ◽  
Northern Australia ◽  
The North ◽  
Crocodylus Porosus ◽  
Mandibular Teeth

Utilizing measurements from 1354 C. porosus, we have derived formulae for predicting snout-vent length from 17 other attributes. The specific problem of predicting body size from an isolated head or skull is treated separately and some data are presented on proportional tissue loss in skull preparation. Sexual dimorphism was examined, and is demonstrated in interocular width, the width at the midpoint of the cranial platform, and the length of the tail. Discriminant analysis has been used to distinguish males from females on the basis of external measurements of both the whole animal and the isolated head. Hatchling C. porosus from Arnhem Bay and the Blyth River have longer heads than those from the Liverpool River. C. porosus from Sarawak have longer tails and are heavier than those from northern Australia. Predicting the maximum size of C. porosus from large skulls in museums is difficult because of variations in basic skull shape. The body size at which mandibular teeth protrude through the premaxilla is quantified.

The pattern of growth in the early lifecycle of individual Sepia pharaonis

2004 ◽  
Vol 55 (4) ◽  
pp. 415 ◽  
Author(s):  
Jonathan W. Minton
Keyword(s):  
Growth Rate ◽  
Growth Phase ◽  
Growth Curves ◽  
Maximum Size ◽  
Control Group ◽  
Sepia Pharaonis ◽  
Second Growth ◽  
The Mean ◽  
R Value ◽  
The Individual

The pattern of growth in the early lifecycle of the pharaoh cuttlefish, Sepia pharaonis, was investigated by rearing hatchlings at 26°C in two separate trials. In each trial, the mean weight and mantle length (ML) was recorded in 5-day intervals. In addition, in each trial the growth of 20 group-reared cuttlefish was measured as a control to compare against the individual data. After 60 days of growth, the mean size for individuals in trial 1 was 2.75 g (maximum size 3.32 g) and in trial 2 was 12.76 g (maximum size 14.99 g) at 90 days. Each individual went through distinct growth phases during the first 90 days after hatching. The first growth phase matched exponential curves with an R-value of 0.98 or better, and the second growth phase corresponded with linear and power growth curves at an R-value of 0.98 or better. In trial 1, the mean growth rate for individuals during the first phase was 5.91% BW day–1 and the control group growth rate was 6.36% BW day–1. In trial 2, the mean growth rate for individuals during the first phase was 6.06% BW day–1 and the control group growth rate was 6.70% BW day–1.

An Aerial Survey of Potential Nesting Areas of the Saltwater Crocodile, Crocodylus porosus Schneider, on the North Coast of Arnehem Land, Northern Australia

1978 ◽  
Vol 5 (3) ◽  
pp. 401 ◽  
Author(s):  
WE Magnusson ◽  
GC Grigg ◽  
JA Taylor
Keyword(s):  
Coastal Wetlands ◽  
Aerial Survey ◽  
North Coast ◽  
Northern Australia ◽  
National Library ◽  
The North ◽  
Arnhem Land ◽  
Saltwater Crocodile ◽  
Different Types ◽  
Crocodylus Porosus

Results of a study of habitats used by C, povosus for nesting on the Liverpool and Tomkinson Rivers, Arnhem Land, northern Australia, are presented. These were used as the basis of an aerial survey for potential crocodile nesting habitat in coastal wetlands between Smith Point (Cobourg Peninsula) and Gove. General conclusions of the survey are given, and areas in which different types of management could be applied are indicated. Detailed results are lodged with the Australian National Library,Canberra (catalogue No. MS5640).

The Nesting of Crocodylus porosus in Arnhem Land, Northern Australia

Copeia ◽  
1977 ◽  
Vol 1977 (2) ◽  
pp. 238 ◽  
Author(s):  
Grahame J. W. Webb ◽  
Harry Messel ◽  
William Magnusson
Keyword(s):  
Northern Australia ◽  
Arnhem Land ◽  
Crocodylus Porosus

Population-Dynamics and Status of Crocodylus-Porosus in the Tidal Waterways of Northern Australia

1986 ◽  
Vol 13 (1) ◽  
pp. 71 ◽  
Author(s):  
H Messel ◽  
GC Vorlicek
Keyword(s):  
Population Dynamics ◽  
Population Model ◽  
Total Population ◽  
Population Management ◽  
Northern Australia ◽  
Night Time ◽  
Management Implications ◽  
Arnhem Land ◽  
Crocodylus Porosus ◽  
Large Animals

The results of 10 years of systematic, standardized, night-time surveys of C. porosus in c. 100 tidal waterways in northern Australia are presented. One group of waterways in Arnhem Land has been studied intensively, especially over the last 4 years; others have been surveyed at least once and many several times. The results indicate a basically steady total population, with some signs of an increase in the proportion of large animals. As total protection has been accorded C. porosus since 1972, these results are perhaps surprising. The results of our surveys and studies have allowed a picture of C. porosus population dynamics in northern Australia to be developed, and this is presented in some detail. It enables us to account in a consistent fashion for the results of the surveys and to predict results to be expected on future surveys. The results also enable us to make an assessment of the overall status of C. porosus in northern Australia, and of the prospects for recovery of the population. Management implications of the results and population model are also discussed.

Movement and Dispersal Patterns of Crocodylus porosus in some Rivers of Arnhem Land, Northern Australia

1978 ◽  
Vol 5 (2) ◽  
pp. 263 ◽  
Author(s):  
GJW Webb ◽  
H Messel
Keyword(s):  
Opposite Direction ◽  
Northern Australia ◽  
Dispersal Patterns ◽  
Capture Site ◽  
Arnhem Land ◽  
Crocodylus Porosus

The dispersal of juvenile C. povosus hatched in the Liverpool River is described. Of those initially caught when hatchlings, 1-y-olds and 2–4-y-olds, and recaught 1 year later, 93 %, 73% and 57% respectively were within 10 km of the original capture site. Movements of up to 21 km in one direction in 1 year could be followed by a similar movement in the opposite direction the following year. Relocated C. povosus demonstrated a homing instinct. A possible explanation for the long distances travelled by some juveniles (up to 81 km in a year), is that chance wandering placed them in the mouth of another stream, and attempts to 'home' in the new stream took them further away from their original capture site. The distribution of C. povosus in other rivers can be explained by dispersal patterns similar to those found in the Liverpool River. Some rivers seem to have supported successful C. povosus breeding for a number of years, others seem to have been sporadically successful, and still others unsuccessful. Movement of juveniles from 'successful' to 'unsuccessful' rivers could account for older juveniles found in the latter type of river.

scholarly journals Assessment of the Growth and Reproductive Performance of Cloned Pietrain Boars

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2053
Author(s):  
Junsong Shi ◽  
Baohua Tan ◽  
Lvhua Luo ◽  
Zicong Li ◽  
Linjun Hong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Growth Performance ◽  
Reproductive Performance ◽  
Semen Quality ◽  
Small Body ◽  
Economic Benefits ◽  
Large Animal ◽  
Significant Difference ◽  
F1 Progeny

How to maximize the use of the genetic merits of the high-ranking boars (also called superior ones) is a considerable question in the pig breeding industry, considering the money and time spent on selection. Somatic cell nuclear transfer (SCNT) is one of the potential ways to answer the question, which can be applied to produce clones with genetic resources of superior boar for the production of commercial pigs. For practical application, it is essential to investigate whether the clones and their progeny keep behaving better than the “normal boars”, considering that in vitro culture and transfer manipulation would cause a series of harmful effects to the development of clones. In this study, 59,061 cloned embryos were transferred into 250 recipient sows to produce the clones of superior Pietrain boars. The growth performance of 12 clones and 36 non-clones and the semen quality of 19 clones and 28 non-clones were compared. The reproductive performance of 21 clones and 25 non-clones were also tested. Furthermore, we made a comparison in the growth performance between 466 progeny of the clones and 822 progeny of the non-clones. Our results showed that no significant difference in semen quality and reproductive performance was observed between the clones and the non-clones, although the clones grew slower and exhibited smaller body size than the non-clones. The F1 progeny of the clones showed a greater growth rate than the non-clones. Our results demonstrated through the large animal population showed that SCNT manipulation resulted in a low growth rate and small body size, but the clones could normally produce F1 progeny with excellent growth traits to bring more economic benefits. Therefore, SCNT could be effective in enlarging the merit genetics of the superior boars and increasing the economic benefits in pig reproduction and breeding.

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