Relationships among egg size, energy reserves, growth rate, and fasting resistance of Canada Goose goslings from southern Ontario

1988 ◽  
Vol 66 (4) ◽  
pp. 957-964 ◽  
Author(s):  
V. G. Thomas ◽  
H. C. Peach Brown

Eggs of wild giant Canada Geese (Branta canadensis maxima) breeding in southern Ontario were collected and incubated artificially. Components of the total nutrient reserve of goslings were measured at hatch to test whether relationships existed between egg size, gosling weight, and weight of reserves in goslings. The growth rate of fed goslings of different weights at hatch was measured for 25 days. The nutrient reserves remaining in goslings of different hatch weights were measured after 2, 4, and 6 days of starvation. Egg size and gosling weight were not highly correlated in this population (r = 0.63). Larger goslings generally contained more reserves than small goslings (P < 0.05), but much variability occurred in this relationship. Gain in weight over 25 days was not related to the weight at hatch. Starved goslings with higher body fat levels had significantly higher dry carcass weights than goslings with low body fat levels (P < 0.01), suggesting a sparing action of fat on body tissues. The apparent survival of small goslings and goslings with small reserves, combined with the great variability in egg size, gosling weight, and extent of metabolic reserves, suggests relaxed selection in the southern Ontario environment where this population breeds.

1985 ◽  
Vol 63 (8) ◽  
pp. 1765-1772 ◽  
Author(s):  
S. K. Mainguy ◽  
V. G. Thomas

Changes in proximate body composition were analyzed in nonmigratory giant Canada geese (Branta canadensis maxima) from Toronto, Ont. (43°37′N, 79°20′W), collected during early and late egg laying in 1980 and 1981, and during incubation and moult in 1981. Early nesting geese had more fat, though not more protein, than late nesting birds in both years. Geese collected in 1981 had more fat and protein than geese collected in 1980. Early and late laying females in both years lost on average 198 g (26%) of fat and 34 g (5%) of protein from the beginning to the end of laying. Fifty-eight percent of the fat reserves possessed at the beginning of laying were lost during incubation. Fat reserves of prelaying Branta canadensis interior nesting on the James Bay lowland (53°15′N, 82°09′W) in 1980 were 9% greater than those of B. c. maxima nesting in Southern Ontario. During the moult at Toronto, Canada geese lost weight from flight muscles while gaining weight in other muscles and in fat. This pattern is seen in waterfowl moulting at several latitudes, and indicates that geese moulting in both southern and northern latitudes probably rely on nutrients in food rather than in body tissues to supply growing feathers.


Author(s):  
Dio Patria Yustysi ◽  
Fajar Basuki ◽  
Titik Susilowati ◽  
Tristiana Yuniarti

ABSTRAK Penelitian ini bertujuan untuk mengetahui pengaruh dari hibridisasi ikan nila Pandu F6 dengan nila Nilasa terhadap karakter reproduksinya dan performa benih yang dihasilkan. Penelitian ini dilakukan dengan metode eksperimental menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 3 kali ulangan. Perlakuan dalam penelitian ini: perlakuan A (Pandu F6 ♀><Pandu F6 ♂), B (Nilasa ♀><Nilasa ♂), C (Pandu F6 ♀>< Nilasa ♂), dan D (Nilasa ♀><Pandu F6 ♂). Data yang diamati meliputi fekunditas, daya tetas telur, diameter dan bobot telur, panjang dan bobot larva TL, panjang dan bobot larva lepas kuning telur, kelulushidupan, laju pertumbuhan spesifik, konversi pakan dan kualitas air. Hasil penelitian menunjukan nilai terbaik pada fekunditas sebesar 1191,67 ± 239,45 butir/200 g, daya tetas telur sebesar 80,93 ± 3,90%, kelulushidupan sebesar 81,55 ± 7,54%, laju pertumbuhan spesifik sebesar 7,26 ± 0,25, konversi pakan 0,54 ± 0,02 didapatkan pada perlakuan C, akan tetapi untuk diameter dan bobot telur, panjang dan bobot larva Kuning Telur, dan panjang dan bobot larva lepas kuning telur tidak berbeda nyata. Hasil tersebut menunjukan bahwa hibridisasi (perlakuan C) memberikan pengaruh yang nyata (P < 0,05) terhadap fekunditas, daya tetas telur, kelulushidupan, laju pertumbuhan spesifik, dan konversi pakan tetapi tidak berpengaruh terhadap diameter dan bobot telur, panjang dan bobot larva, dan panjang dan bobot larva lepas kuning telur. Kata kunci: Hibridisasi, Ikan Nila, Karakter Reproduksi, Performa Benih  ABSTRACT This research aims to know the influence of hybridization tilapia fish Pandu F6 with nila Nilasa against the character of the reproduction and seed performance. This research was conducted with the experimental method using Random Design complete (RAL) with 4 treatments and three replicates. The treatments in this study: the treatment A (Pandu F6 F6 ♀ >< Pandu ♂), B (Nilasa ♀>< Nilasa ♂), C (Pandu F6 ♀>< Nilasa ♂), and D (Nilasa ♀ >< Pandu F6 ♂). The observed data covering fecundity, hatching rate, egg size, yolk sack larva length and weight, length and weight of the egg yolk off larvae, survival rate, specific growth rate, feed conversion rate, and water quality. The results showed the best value on the fecundity of 1191.67±239.45 eggs/200 g, Hatching rate 80.93 ± 3.90%, Survival rate of 81.55 ± 7.54%, specific growth rate of 7.26 ± 0.25, conversion fodder 0.54 ± 0.02 obtained at the treatment C, but for the diameter and weight of egg, larval length and weight TL, and the length and weight of the yolk egg off larvae for each treatment do not differ markedly. The results showed that hybridization (treatment C) gives a real influence (P < 0.05) of fecundity,hatching rate, survival rate but not with the egg size, larva weight and length, and the length and weight of larvae off yolk. Water quality on the spawning, hatching eggs and larvae found on the maintenance of a decent range for tilapia fish farming Keywords: hybridization, tilapia fish, character of the reproduction, seed performance 


1992 ◽  
Vol 6 ◽  
pp. 245-245
Author(s):  
Sean H. Rice

The shape of an isometric gastropod shell can be described completely by specifying the pattern of shell secretion around the aperture (relative to aperture size) and the growth rate of the aperture itself. These descriptors provide a “natural” morphometric in that they correspond to the specific biological processes involved in constructing the shell.Describing shell form in this way allows us to specify what developmental changes must occur during the transition of one shell form to another. In particular, we can distinguish between transitions that can occur through purely heterochronic processes (changes in growth rate) and those that require a change in the specific pattern in which cells of the mantle lay down shell. We can also investigate just what changes occur during the ontogeny of non-isometric shells.Any change in either the pattern of shell secretion or the growth rate of the animal leads to changes in a number of classical morphometric measures, such as apex angle and whorl expansion rate. Those transformations resulting from changes in growth rate, however, are much more predictable than those resulting from changes in the pattern of shell production. A slight increase in the growth rate of the animal, for instance, produces a correspondingly slight increase in the apex angle and the rate of whorl expansion. By contrast, the consequences of a slight change in the pattern of shell production are highly sensitive to just how that change was achieved.Data from 8 genera of marine snails show that the variance within each genus, relative to the variance among all genera, is smaller for measures of aperture shape (which can only be altered through a change in the pattern of secretion of shell material) than for characters that can change through heterochronic transformations (such as apex angle). Furthermore, the shell forms of a number of non isometric shells can be described by a constant pattern of shell production and a variable growth rate.Heterochronic changes thus appear to be the preferred mechanism for changing phenotype in gastropod shells. Those characters that can only be altered by changing the pattern of shell production around the mantle, such as aperture shape, appear to be more conservative than those that can be changed through purely heterochronic transitions. This is consistent with the idea that mutations which alter many characters in a highly correlated manner have a higher probability of being favored by selection than those with relatively unpredictable consequences.


1991 ◽  
Vol 69 (3) ◽  
pp. 744-747 ◽  
Author(s):  
Lyle A. Renecker ◽  
W. M. Samuel

Growth rate and potential, 25 hand-reared mule deer (Odocoileus hemionus hemionus) were examined. When possible, body weights of all animals were recorded weekly. Female deer matured faster than males, but males attained a larger body size. Regressions of winter weight loss of both sexes on peak autumn weight were highly correlated. Similarly, spring and summer compensatory gain in females could be predicted from the minimum spring weight. Annual cycles of intake and weight gain may have adaptations that improve reproductive success and winter survival.


2019 ◽  
Vol 161 (1) ◽  
pp. 103-113
Author(s):  
Juan Rodríguez-Ruiz ◽  
Mónica Expósito-Granados ◽  
Jesús M. Avilés ◽  
Deseada Parejo

The Auk ◽  
2000 ◽  
Vol 117 (4) ◽  
pp. 971-979 ◽  
Author(s):  
Margaret C. MacCluskie ◽  
James S. Sedinger

Abstract We determined patterns of nutrient-reserve use by female Northern Shovelers (Anas clypeata) nesting at Minto Flats, Alaska, and compared them with those of female shovelers nesting in the Prairie Pothole Region of Manitoba, Canada. Individual variation in somatic lipid was best explained by nest initiation date; females that initiated nests early had larger lipid reserves than females that delayed nest initiation. These results contrast with those from Manitoba, which showed that females used lipid reserves and stored protein during egg production. Incubating females from Alaska did not use protein or mineral reserves, but lipid reserves decreased significantly throughout incubation. Females in Alaska and Manitoba used lipid reserves similarly during incubation. We conclude that endogenous nutrient availability does not proximately limit clutch size during laying for this population of shovelers, possibly due to the high productivity of wetlands in interior Alaska and/or the long photoperiod that allow females to forage extensively. Successful completion of incubation or brood rearing may be an ultimate factor that controls clutch size for this population of shovelers.


The Auk ◽  
1984 ◽  
Vol 101 (2) ◽  
pp. 361-370 ◽  
Author(s):  
C. Davison Ankney

Abstract I collected 150 Brant (Branta bernicla) at East Bay, Southampton Island, Northwest Territories, Canada, in 1979 and 1980 to evaluate how much these birds rely on reserves of fat, protein, and calcium during egg production, incubation, and the subsequent wing molt. Egg laying resulted in decreases in body weight and nutrient reserves of females. These decreases could have accounted for all of the fat but only 70% of the protein in an average clutch. Neither males nor females had sufficient reserves when incubation began to enable them to fast during that period. Only 11% and 22% of the energy required by males and females, respectively, could have been derived from their reserves during incubation. Brant evidently did not use body reserves to obtain nutrients for feather growth during wing molt. Rather, molting males and females accumulated muscle protein, which supports my hypothesis that wing molt is not a nutritional stress for waterfowl.


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