Captures, Body Mass and Diet of Platypuses in a Subalpine Tasmanian Lake.

1998 ◽  
Vol 20 (2) ◽  
pp. 311
Author(s):  
S.A. Munks ◽  
H.M. Otley ◽  
J. Jackson ◽  
M. Hindell
Keyword(s):  
Body Mass ◽  
Early Spring ◽  
Late Winter ◽  
Adult Males ◽  
Catch Per Unit Effort ◽  
Doubly Labelled Water ◽  
Food Items ◽  
Adult Females ◽  
Unit Effort ◽  
Significant Difference

Studies into the ecology of the platypus have concentrated on populations inhabiting !otic waters on mainland Australia. This paper presents preliminary results of a study into the feeding ecology and energetics of the platypus in a subalpine lake in Tasmania. During the autumn, winter and early spring months 29 individual platypuses were captured (13 adult females, 13 adult males and 3 juveniles). Of these, 46% of the adult males, 31% of the adult females and one of the juveniles were recaptured between one and eight times. Catch per unit effort was similar for the 1800-2400hrs, 0600-1200hrs and 1200-1800hrs time periods (0.158, 0.161 and 0.156, respectively). However catch per unit effort was low (0.057) between 2400hr and 0600hrs. There was no significant difference in the mean body mass of adult males and females between autumn, winter and early spring, however the condition of the females, indicated by the tail fat index, decreased in early spring. The overall mean body mass for adult males and adult females caught during the autumn/winter and early spring months was 2293.21g ± 300 (1920-2740g) and 1375.22g ± 147 (1150-1580g), respectively. This supports the observation that platypuses in Tasmania are larger than those occurring in mainland water bodies. The timing of juvenile captures suggests that matings occur at Lake Lea between mid September through to January. This indicates that the breeding season may be later in Tasmania than on the mainland. The contents of cheek pouches were collected from individuals caught during the autumn, winter and early spring months for identification of food items. Food items identified so far include Trichoptera, Gastropod molluscs, Ephemeroptera nymphs, Coleoptera larvae and Diptera, with Trichoptera forming the dominant food item. Measurements of the daily energy expenditure of six adults were attempted during late winter and early spring using the doubly labelled water technique.

scholarly journals Diet Composition and Seasonal Fluctuations in the Feeding Habit of Snow Barbel (Schizothorax plagiostomus) in River Indus, Pakistan

2018 ◽  
Vol 46 (1) ◽  
pp. 8
Author(s):  
Muhammad Qayash Khan ◽  
Muhammad Zubair Anjum ◽  
Shamim Akhter ◽  
Irfan Khattak ◽  
Abid Ali
Keyword(s):  
Diet Composition ◽  
Feeding Activity ◽  
Fish Fauna ◽  
Feeding Habit ◽  
Gut Contents ◽  
Catch Per Unit Effort ◽  
Food Items ◽  
Unit Effort ◽  
Significant Difference ◽  
River Indus

Background:Schizothorax plagiostomus is widely distributed in river Indus and is most important food fish in Pakistan. The feeding habit of fish is directly related to the size of fish, its metabolic rate and environmental temperature. The accurate description of fish diet and feeding habit is a very important aspect in fisheries management for the purpose of species conservation, breeding and culture. The present work was aimed to investigate the specie abundance, the diet composition and seasonal variations in the feeding habit of Snow barbell Schizothorax plagiostomus.Materials, Methods & Results: A total of 1799 fish specimens were caught at the confluence of six tributaries along river Indus at Indus Kohistan, northeastern Pakistan. The fish were collected by 5-panels of gill net during first week of each month. The site specific Catch Per Unit Effort (CPUE) and season specific CPUE of fish fauna were assessed. For the gut content analysis 240 samples (99 male and 141 females) of S. plagiostomus were selected on monthly basis. Frequency of occurrence method and volumetric method were applied to record the different food items in the gut of S. plagiostomus. The physico-chemical parameters, NO3 concentration and dissolved Co2 of water from different localities of river Indus were recorded month wise by Hach sensION 156 meter, Horiba LAQUA Nitrate Meter and EA80 meter respectively. Significant difference was observed in water temperature during the four seasons. Except alkalinity no other water parameter showed significant variation across different localities. The results showed that highest Mean CPUE was observed for Darel Stream (0.55) and lowest for Jalkot stream (0.26). Peak abundance of fish was recorded in the month of November with a mean catch of 44.50, mean CPUE of 0.74 and mean Kruskal-Wallis rank value of 63.25. Spirogyra and Ulothrix occurred as maximum food items in the gut of S. plagiostomus during summer while their minimum amount occurred during autumn. According to the ranking index spirogyra and ulothrix ranked higher with significant difference in comparison to other food items. The results showed that S. plagiostomus is phytophagous in its feeding habit, which consumed mainly algae attached to stones and pebbles during the whole year. However, the presence of some secondary items such as animal matter, detritus, sand and mud might be due to the distinct availabilities of food along the seasons. The highest feeding activity of S. plagiostomus was recorded during summer while the lowest one occurred during autumn, spring and winter. Discussion: Catch per unit effort (CPUE) is an indirect measure of the abundance of a target species. It is used as an index of stock abundance in fisheries and conservation biology. During the study low fish fauna was found in River Indus as reported previously. Majority of the fish occurred in snow fed river tributaries in the study area as these tributaries are comparatively less turbulent. Previous studies have also recorded that Schizothoracine generally prefer clean waters. The present findings of gut contents analysis showed clearly that S. plagiostomus is a phytophagous fish which scrap and consumed spirogyra and ulothrix attached to stones and pebbles. Earlier it was reported that mouth of S. plagiostomusis is inferior, wide, with deep lower jaw having keratinized cutting edge and the lower lip is folded and expanded with numerous papillae making it best suited for scrapping algae attached to stones and pebbles. The highest feeding activity was observed during warmer months as compared to cold months. S. plagiostomus spawn twice in a year in autumn and in spring. The highest feeding activity of S. plagiostomus seems to be link with a reflex of recovery strategy due to physiological process of gonadal development.

scholarly journals The effect of escape gaps of cylinder folding traps on fish catch at the coastal waters of Tuban Regency

2021 ◽  
Vol 322 ◽  
pp. 03002
Author(s):  
Farrel Nafis Adyatama ◽  
Ghassan Nurul Huda ◽  
Nahla Alfiatunnisa ◽  
Faizal Rachman ◽  
Supardjo Supardi Djasmani ◽  
...  
Keyword(s):  
Coastal Waters ◽  
Marine Organisms ◽  
Total Weight ◽  
Total Catch ◽  
Catch Per Unit Effort ◽  
Unit Effort ◽  
Significant Difference ◽  
Fish Catch ◽  
Swimming Crabs

The purpose of this study is to determine the effect of the escape gap of cylinder folding trap on catch per unit effort (CPUE), trap rate, composition, and size of fish caught in the coastal waters of Tuban Regency. The research was conducted in November 2019 by deploying 60 units in ten experimental fishing trips at different locations. The traps were 20 units without escape gap, 20 units with an escape gap of 3 cm x 6 cm, and 20 units with an escape gap of 4 cm x 7 cm. Overall, the experiments resulted in a collection of 22 species of marine organisms, such as swimming crabs (33% of total weight), snails, shrimps, crabs, fishes (55% of total weight), and cuttlefish. The highest CPUE was found for the traps with escape gaps of 4 cm x 7 cm, i.e., 9.18 gr/trap/trip. There was no significant difference in the total catch, the weight of catches, trap rate, and catch per unit effort (CPUE) among the three types of traps.

Aggregating Behavior of Ovigerous Female Red King Crab, Paralithodes camtschaticus, in Auke Bay, Alaska

1993 ◽  
Vol 50 (4) ◽  
pp. 750-758 ◽  
Author(s):  
Robert P. Stone ◽  
Charles E. O'Clair ◽  
Thomas C. Shirley
Keyword(s):  
Shallow Water ◽  
Nearest Neighbor ◽  
Ovigerous Female ◽  
Early Spring ◽  
Late Winter ◽  
Red King Crab ◽  
Paralithodes Camtschaticus ◽  
Adult Males ◽  
Age Classes ◽  
King Crab

Ovigerous female red king crab, Paralithodes camtschaticus, monitored with ultrasonic biotelemetry, displayed distinct seasonal shifts in habitat use and bathymetric distribution. Crab occupied deep water between June and mid-November, relatively shallow water between mid-November and early March, and returned to deeper water prior to molting and mating in spring. Females were nonrandomly distributed within both depth ranges but seasonally changed their behavior and degree of association with conspecifics. Tagged crab were more aggregated (lower mean nearest neighbor distances) in winter than in summer and fall (F-test, P < 0.01). Winter SCUBA observations supported these results; females of mixed age-classes formed dense aggregations in shallow water, and crab exhibited "podding" behavior similar to that reported for younger age-classes. Adult males were associated with aggregations during late winter and early spring. Observations from the manned submersible Delta indicated that females were nonrandomly distributed in the deepwater habitat as well and probably formed loosely knit feeding aggregations there. Seasonal changes in aggregation densities and benthic areas used were the same during the two consecutive years of this study.

scholarly journals Seasonality of Mansonia titillans during dam construction, Biritiba-Mirim, São Paulo State, Brazil

2013 ◽  
Vol 13 (1) ◽  
pp. 70-73 ◽  
Author(s):  
Frederico Alves D'Avila ◽  
Almério de Castro Gomes
Keyword(s):  
Early Spring ◽  
Dry Season ◽  
Southeastern Brazil ◽  
Rank Test ◽  
Late Winter ◽  
Dam Construction ◽  
Wet Season ◽  
Paulo State ◽  
Significant Difference ◽  
Wilcoxon Rank Test

A two and a half year survey was conducted at a dam in southeastern Brazil. Shannon Traps were used for sampling. Kruskal-Wallis test showed little relation between rainfall and abundance. The data clearly show three abundance peaks, all of them in the end of the dry season, in consonance with the scarce literature existent. Although Kruskal-Wallis Test did not find a clear preference for the dry season, Pairwise Wilcoxon Rank Test revealed a significant difference between Fall and Spring samples. Ma. titillans population had a peak on late winter/early spring, close to the begin of wet season.

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.

scholarly journals The Diet and Sexual Differences of the Caspian Bent-Toed Gecko,Tenuidactylus caspius(Squamata: Gekkonidae), in Northern Iran

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Vida Hojati ◽  
Reza Babaei Savasari
Keyword(s):  
Sexual Dimorphism ◽  
Culex Pipiens ◽  
Tail Length ◽  
Adult Males ◽  
Northern Iran ◽  
Widespread Distribution ◽  
Adult Females ◽  
Significant Difference ◽  
Males And Females ◽  
Prey Items

The Caspian bent-toed gecko,Tenuidactylus caspius, is one of the most common nocturnal lizards of Iran with widespread distribution especially in the northern provinces. This research was done in order to study the diet and sexual dimorphism of this species in Sari County from 5 May to 20 October. During this research, 40 specimens of them including 20 males and 20 females were studied for diet and 140 specimens including 70 adult males and 70 adult females were studied for sexual dimorphism. Prey items identified were insects that belong to 15 species of 8 families and 6 orders. The most common prey items wereCulex pipiensandMusca domestica. There is no significant difference between diets of males and females. Results show that the adult males in addition of having the apparent femoral and preanal pores are heavier than females and have larger body, head, and tail length.

Seasonal changes in body mass and body composition of ringed seals (Phoca hispida) on Svalbard

1990 ◽  
Vol 68 (3) ◽  
pp. 470-475 ◽  
Author(s):  
Morten Ryg ◽  
Thomas G. Smith ◽  
Nils Are Øritsland
Keyword(s):  
Body Composition ◽  
Body Mass ◽  
Seasonal Changes ◽  
Adult Males ◽  
Phoca Hispida ◽  
Core Mass ◽  
Adult Females ◽  
Ringed Seals ◽  
Body Fat Content ◽  
Body Mass Changes

Seasonal changes in body mass and body composition of ringed seals (Phoca hispida) from the Svalbard Islands are described. The blubber content of adult females decreased from a high of about 50% at the beginning of the pupping season in March–April to a low of 31% during moulting in June. In adult males, the blubber content decreased from 41% in March to 29% in June. By estimating an individual seal's body mass by 1 April from its standard body length, we calculated an average daily loss of body mass of 160 g/day in adult females and 100 g/day in adult males from the start of lactation to the middle of moulting. The blubber content of sexually immature seals was less in June and July than in April, but the seasonal changes were smaller than in adult seals. We found no evidence of significant changes in core mass in adult seals, and suggest that the seasonal body mass changes are mostly due to changes in body fat content.

scholarly journals Some endocrine traits of transgenic rabbits. I. Changes in plasma and milk hormones

2008 ◽  
pp. 735-744
Author(s):  
AV Sirotkin ◽  
P Chrenek ◽  
J Rafay ◽  
R Omelka ◽  
H Vetr ◽  
...  
Keyword(s):  
Blood Plasma ◽  
Body Mass ◽  
Litter Size ◽  
Transgenic Animals ◽  
Adult Males ◽  
Young Females ◽  
Adult Females ◽  
Transgenic Rabbits ◽  
Human Factor Viii ◽  
Igf I

The aim of these studies was to compare some endocrine and non-endocrine characteristics of transgenic (carrying mammary gland-specific mWAP-hFVIII gene construct) and non-transgenic rabbits. The concentrations of corticosterone, progesterone, testosterone, estradiol, insulin-like growth factor I (IGF-I) and human factor VIII (hFVIII) in the blood plasma of adult females (9 months of age, 3rd generation transgenic animals), adult males, and young females (1-2 months of age, 4th generation of transgenic animals), as well as in the milk of lactating adult females, were analyzed by using RIA. In addition, litter size and body mass of pups born by transgenic and non-transgenic females from the 3rd generation were compared. Transgenic animals were compared with their non-transgenic siblings (the same genetic and epigenetic background). Transgenesis did not influence plasma hFVIII, but significantly increased corticosterone (in all animals), reduced IGF-I (in adult males and females), testosterone and estradiol, (in young females) and altered progesterone (increase in adult males and decrease in adult females) concentrations in blood plasma. In addition, transgenic females had higher milk concentrations of testosterone, but not progesterone or IGF-I than their nontransgenic sisters. These endocrine changes were not associated with changes in litter size. Transgenic male (but not female) pups have smaller body mass than control animals. These observations demonstrate the influence of transgenesis per se on the animal growth and endocrine system (secretion of reproductive and stress steroid hormones as well as growth factors) over four generations.

scholarly journals Pêche Et Caractéristiques Morphologiques D’un Poisson-Chat Endémique Synodontis Punctifer (Daget, 1964) Dans Le Barrage Électrique De Taabo (Côte d’Ivoire)

2018 ◽  
Vol 14 (15) ◽  
pp. 101
Author(s):  
Hervé Oussou Koffi ◽  
Diaha N’guessan Constance ◽  
Soro Yaya ◽  
N’Da Konan
Keyword(s):  
Sex Ratio ◽  
Condition Factor ◽  
Morphological Characteristics ◽  
Fishing Effort ◽  
Annual Production ◽  
Allometric Growth ◽  
Catch Per Unit Effort ◽  
Large Size ◽  
Unit Effort ◽  
Significant Difference

A study of Synodontis punctifer (family: Mochokidae) of Taabo Lake was conducted from October 2015 to September 2016. This was carried out so as to evaluate its quantity (biomass) caught by fishing and also its morphological characteristics. The fish were caught using gillnets at 4 sites of the lake and different measurements were made. The fishing effort was 23 to 11 fishermen / day in Taabo city, 17 to 11 fishermen / day in Courandjourou, 13 to 5 fishermen / day in Ahondo, and 8 to 3 fishermen / day in Taabo village. The catch per unit effort (CPUE) ranged from 17.7 to 3.7 g / fisherman / day, 9.2 to 1.2 g / fisherman / day, 8.3 to 0.7 g / fisherman /day, 8 to 1g / fisherman / day at Ahondo, Courandjourou, Taabo city and Taabo village, respectively. The overall annual production was estimated at 2199.3 kg, i.e. 817 kg (40%) at Ahondo, 788.3 kg (35%) at Courandjourou, 462.5 kg (20%) at Taabo, and 131.5 kg (5%) in Taabo village. The overall sex ratio (1: 1.33) was in favor of females. Individuals have negative allometric growth at all sites with values ranging from 1.72 to 2.89. The condition factor does not vary significantly between different categories of individuals (ANOVA, F = 2.79, p ˃ 0.05). A significant difference was observed between the average sizes of the individuals of the different sites (test, p˂0,05). The large size specimens were captured at Ahondo, mean (avg = 15.38 ± 1.68 cm FL). In Courandjourou, the sizes were intermediate (avg = 13.63 ± 1.64 cm LF). Smalls sizes have been observed in Taabo city (mean= 12.37 ± 1.24 cm FL) and Taabo village (mean= 15.58 ± 1.58 cm FL).

scholarly journals Status and biology of ringed seals (Phoca hispida) in Svalbard

1998 ◽  
Vol 1 ◽  
pp. 46 ◽  
Author(s):  
Christian Lydersen
Keyword(s):  
Body Mass ◽  
Dive Duration ◽  
Early Spring ◽  
Ringed Seal ◽  
The Arctic ◽  
Polar Cod ◽  
Net Energy ◽  
Adult Males ◽  
Ringed Seals ◽  
Males And Females

The ringed seal is the most abundant mammal in the Svalbard area. Annual pup production in this area is estimated to be 20,000. No systematic harvest records exist, but some few hundred seals are taken annually, mainly for dog food. The ringed seals in Svalbard are protected from hunting in the period 15 March - 15 April. Peak pupping season is the first week of April. New-born ringed seals weigh an average of 4.6 kg. They are nursed for about 39 days, and weaned at an average body mass of around 22 kg. During the period of maternal care pups consume a total of about 54 litres of milk, that is composed of approximately 38% fat and 10% protein. Asymptotic standard lengths and body masses for adult ringed seal males and females are 131.5 and 127.8 cm, and 52.6 and 59.9 kg,respectively. The maximum values recorded for lengths of males and females in Svalbard are 157 cm and 107 kg, respectively. There is marked seasonal variation in body mass in both sexes with the highest mass records being recorded in early spring before pupping occurs, and with minimum values in the summer after the breeding and moulting seasons. The observed variation in mass is mainly due to changing blubber thickness of the seals. Ringed seal males attain sexual maturity at the age of 5 - 7 years, while females reach maturity when they are 3-5 years of age. The oldest seal collected in Svalbard was aged 45. Ringed seals in the Svalbard area feed on a variety of prey organisms, the most important of which are polar cod (Boreogadus saida) and the crustaceans Parathemisto libellula, Thysanoessa inermis and Pandalus borealis. Ringed seal pups start diving during the nursing period while they are still white-coats, and spend about 50% of the time in thewater prior to weaning. They are capable of diving for up to 12min and dive to the bottom of the study areas (max. 89 m). Nursing females spend more than 80% of their time in the water. Maximum recorded dive duration for mothers was 21.2 min. In order to produce a weaned pup, the net energy expenditure for a ringed seal mother is 1,073 MJ. This energy value corresponds to the consumption of 185 kg of polar cod or 282 kg of P. libellula. The annual gross energy consumption for adult males and females is calculated to be 5,600 MJ and 7,300 MJ, respectively. The main predators of ringed seals in Svalbard are polar bears (Ursus maritimus) and Arctic foxes (Alopex lagopus). In addition, both glaucous gulls (Larus hyperboreus) and walruses (Odobenus rosmarus) are documented as predators of ringed seals in this area. Heavy predation pressure is probably the main factor explaining why pups of this species start diving at such a young age, why they have access to so many breathing holes (8.7 on average) and why they keep their white coat long after its thermoregulatory properties have vanished. Pollution levels in ringed seals from Svalbard are, generally speaking, similar to levels in other areas of the Arctic.

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