Summer food and feeding of the ruddy duck in Manitoba

1973 ◽  
Vol 51 (12) ◽  
pp. 1293-1297 ◽  
Author(s):  
W. R. Siegfried

The food and feeding habits of adult and juvenile ruddy ducks (Oxyura jamaicensis) in southwestern Manitoba were studied during June–August 1971. Animal material predominated in the diets of the birds. The basic diets of adult males and females, as well as ducklings of all ages, were similar. Larval and pupal midges (Tendipedidae), especially Chironomus, constituted the main food item. The quantity of grit in the gizzards increased with the age of the ducklings. There was no significant difference between the average quantities of grit retained by male and female adult birds. Ruddy ducks, of all ages, forage almost exclusively by diving and straining food organisms from the soft muddy ooze on the bottoms of ponds. Foraging ruddy ducks appear to select areas relatively rich in midge larvae.

2017 ◽  
Vol 4 (1) ◽  
pp. 69-72
Author(s):  
Munisha Murali S ◽  
Sheeba S

Knowledge on fish biology is essential for improving aquaculture. The present study was focused on the biology of Puntiusamphibius. The fishes were collected from a freshwater body in parlance known as “Arappa”, located in Thalikulam at Thrissur district in Kerala. This water body is in the vicinity of the sea anddebouches into the marine during monsoon season. In the present investigation 106 fishes were collected during March to August 2006. The study revealed that there was no significant difference observed among the length weight relationship of males and females. Composition of gut content showed that it is a selectivefeeder of Bacillariophyceae and a pronounced omnivore. The gastro-somatic index of female and male was high during May indicating the active feeding during breeding.The sex ratio between males and females was variable and female dominated over males. The fecundity of fish was proportional to the weight of the ovary. Gonado-somatic index was comparatively high during spawning seasons. This is a preliminary lesson on the reproductive biology and certain distinctive characters such as length-weight and food and feeding habits of Puntius amphibius.


1987 ◽  
Vol 114 (2) ◽  
pp. 178-184 ◽  
Author(s):  
Hajime Watanobe ◽  
Kazuo Takebe

Abstract. The cimetidine-induced plasma Prl response was examined in rats of both sexes. First, 10 week old intact adult males and females (dioestrous) were compared. There was no significant difference in the Prl response to cimetidine between the two groups, despite the fact that in adult females the anterior pituitary Prl content was 4 times greater than in males. Second, the effect of gonadal state in adult age on the Prl response to cimetidine was examined in both sexes. In male rats, gonadectomy at the age of 6 weeks significantly reduced the plasma Prl response as well as the pituitary Prl content, both of which were sufficiently restored by testosterone replacement. However, in females, neither gonadectomy at the age of 6 weeks nor subsequent oestradiol replacement affected the Prl response to cimetidine, despite the fact that gonadectomy significantly reduced and oestradiol treatment significantly enhanced the pituitary Prl content. Third, possible permanent effects of the postnatal gonadal milieu on the cimetidine-induced Prl response and the pituitary Prl content were examined in both sexes by castration at varying postnatal ages. The ratio of plasma Prl response to pituitary Prl content was similar in all castrated males. In females, however, the ratio decreased with increasing castration age. In conclusion, the mechanism of cimetidine-induced Prl release is less sex-dependent than are the mechanisms of Prl release by other Prl secretagogues. First, this may be due to a minor role of oestrogen in females in determining the Prl response to cimetidine. Second, the postnatal ovarian secretions may exert a permanent inhibition of the development of the cimetidine-mobilized anterior pituitary Prl pool.


1987 ◽  
Vol 8 (1) ◽  
pp. 13-17 ◽  
Author(s):  
S.P. Gittins

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.


2007 ◽  
Vol 42 (4) ◽  
pp. 525-532 ◽  
Author(s):  
F. Punzo

Laboratory studies assessed the effect of group size on egg-carrying behavior and walking speed of adults of the subsocial beetle, Odontotaenius floridanus Schuster (Coleoptera: Passalidae). Adult males tested solo carried significantly fewer eggs per individual when compared with males tested in groups of 4 and 8 individuals. Similarly, adult males and females in groups of 4 and 8 individuals exhibited significantly faster walking speeds when tested in a linear runway as compared with adults tested alone. There was no significant difference in the number of eggs carried or walking speed between beetles tested in groups of 4 or 8 individuals. This represents the first demonstration of social facilitation in passalid beetles. The adaptive significance of social facilitation in insects is discussed.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Vida Hojati ◽  
Reza Babaei Savasari

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.


2010 ◽  
Vol 124 (12) ◽  
pp. 1251-1256 ◽  
Author(s):  
S Elwany ◽  
A Medanni ◽  
M Eid ◽  
A Aly ◽  
A El-Daly ◽  
...  

AbstractObjective:To establish normative dimensions for the depth of the olfactory fossa, the length and angulation of the lateral lamella of the cribriform plate, and the height of the ethmoid roof, in adult males and females.Design:The study assessed 300 high resolution, multislice computed tomography scans of the paranasal sinuses, which were evaluated using Merge Efilm software (version 2.0.0, build 37).Results:According to the original Keros classification, the type II olfactory fossa was the commonest type in men (66.7 per cent), while the type I fossa was commonest in women (53 per cent). A difference of 3 mm or more between the depths of the right and left olfactory fossae was present in 11 per cent of men and 2 per cent of women. The lateral lamella of the cribriform plate was significantly shorter and less oblique in men than in women. The length of the lateral lamella was greater anteriorly than posteriorly in both sexes. There was a statistically significant difference between the angle of the lateral lamellae, comparing right and left sides. The ethmoid roof was lower in women than men.Conclusion:The observed differences between men and women and between the right and left sides are of surgical importance, and should alert surgeons to the need for thorough, systematic pre-operative evaluation of computed tomography scans.


2016 ◽  
Vol 63 (4) ◽  
Author(s):  
M. Ashiq Ur Rahman ◽  
P. S. Lyla ◽  
S. Ajmal Khan

The feeding ecology and prey preference of greenback grey mullet Liza subviridis (Valenciennes, 1836) were investigated in Parangipettai waters (11°29′25.55″N; 79°45′38.62″E) from May 2011 to April 2012. A total of 328 male and 360 female specimens of L. subviridis were analysed. Detritus and sand particles formed the major food item of L. subviridis in both sexes besides, diatoms, dinoflagellates, algae, zooplankton, foraminiferans, polychaetes and larval forms were also noticed and ranked respectively based on the quantities. Feeding intensity showed that the percentage of ‘empty’ stomachs varied from 7.2% (November 2011) to 19.3% (August 2011) and from 7.1% (March 2012) to 19.2% (August 2011) in males and females respectively whereas the ‘gorged’ stomach in males and females was in the ranges of 4.6% (March 2012) - 14.5% (December 2011) and 4.6% (September 2011) - 14.5% (April 2012). The gastrosomatic index of males and females ranged between 5.9% (October 2011) - 8.2% (May 2011) and 6.1% (March 2012) - 8.1% (May 2011) respectively. The results agree with the previous reports and extend the understanding on its well-being, reproductive seasons and stock of L. subviridis in Parangipettai waters.


1988 ◽  
Vol 7 (3) ◽  
pp. 113-121
Author(s):  
A. C. Kok ◽  
O. B. Kok

Cultivated crops such as maize, sunflower and wheat are the dominant food component of rock pigeons near urban areas, but in more remote rural surroundings natural vegetation forms an important part of the diet. No significant difference is apparent in the overall dietary composition of the respective sex and age groups. Likewise, the number and size of separate food items in the crops of adult males and females are remarkably similar. The average crop mass of both sexes is significantly higher in the late afternoon than in the early morning. The conspicuous seasonal variation in crop mass is apparently related to the relative availability of the food supply. Despite a large degree of dietary overlap, direct competition between rock and feral pigeons is limited to a minimum.


2009 ◽  
Vol 69 (1) ◽  
pp. 137-142 ◽  
Author(s):  
JC. Niemeyer ◽  
VC. Santos ◽  
PB. Araújo ◽  
EM. da Silva

Reproduction of the isopod Cubaris murina was studied in the laboratory in order to observe the offspring number per brood, the number and duration of the incubation periods, and the influence of repeated mating on number of young per brood. An experiment was conducted with two different groups: female/male pairs and females that were isolated after mating. No significant difference was found between the two reproductive female groups for the mean number of young per brood (x = 25) and the duration of the incubation periods (x = 17 days). One mating was enough for at least five broods, with no reduction in brood size. There was no significant difference between the number of adult males and females. Low-density cultures had a significantly higher growth rate compared to high-density cultures. Furthermore, the experimental results for optimization isopod culture conditions for terrestrial ecotoxicity testing are reported.


2017 ◽  
Vol 64 (3) ◽  
Author(s):  
Durga Prasad Behera ◽  
S. Y. Tenjing ◽  
Rocktim Ramen Das ◽  
Laxman Nayak ◽  
D. Mohapatra

The relationship between carapace length (CL), carapace width (CW) and total weight (TW) in the flower moon crab Matuta planipes Fabricius, 1798 was studied and found to be CL = 0.144+1.319 CW and CL = 0.356+1.273 CL for males and females respectively. In case of the carapace width and total weight, the relationships were: TW = 0.272 CW3.011 and TW = 0.474 CW2.555 for males and females respectively. The relationships of carapace length and total weight were: TW = 0.128 CL2.917 for males and TW = 0.184 CL2.650 for females. A linear pattern was found between the relationship of CL and CW for M. planipes, whereas a curvilinear pattern was found between the relationship of CL/CW and TW in the present study. It was also observed that M. planipes is an opportunistic omnivore, seaweed being the most dominant food item followed by crustaceans, seagrass, amphipods and miscellaneous matter.


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