Within-season reproductive and somatic energy allocation in a freshwater clam, Anodonta piscinalis

Oecologia ◽  
1996 ◽  
Vol 105 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Jukka Jokela
Keyword(s):  
Energy Allocation ◽  
Freshwater Clam ◽  
Anodonta Piscinalis ◽  
Somatic Energy

Effect of size-dependent muskrat (Ondatra zibethica) predation on the spatial distribution of a freshwater clam, Anodonta piscinalis Nilsson (Unionidae, Bivalvia)

1995 ◽  
Vol 73 (6) ◽  
pp. 1085-1094 ◽  
Author(s):  
Jukka Jokela ◽  
Pia Mutikainen
Keyword(s):  
Spatial Distribution ◽  
Central Place ◽  
Selection Gradient ◽  
Freshwater Clam ◽  
Size Dependent ◽  
Evolutionary Response ◽  
Spatial Refuge ◽  
Mean Size ◽  
Study Sites ◽  
Anodonta Piscinalis

We studied the effect of central-place foraging by muskrats on the spatial distribution of freshwater clam Anodonta piscinalis. We also analysed the prey-size preference of muskrats. We collected A. piscinalis shells from four muskrat middens representing different prey populations and sampled the clam populations quantitatively. Muskrats had clear effects on the spatial distribution of the clams. At all study sites the area close to shore had no clams. The width of the empty area was correlated with the number of shells found in the muskrat midden. The density of clams decreased and their mean size increased with the distance from muskrat midden at two of the sites. Muskrats did not prey on clams smaller than 50 mm. Muskrats preferred 60- to 70-mm clams at three of the sites and 85- to 90-mm clams at the fourth. In an analysis conducted using ages, a selection gradient on the growth rate of clams was found for three of the study populations. However, spatial refuge from predation and inconsistency of selection may slow down or counterbalance the evolutionary response to predation.

scholarly journals Environmental Influence on Life-History Traits in Male Squid Uroteuthis Edulis With Alternative Reproductive Tactics

2021 ◽  
Author(s):  
Yumeng Pang ◽  
Chih-Shin Chen ◽  
Tomohiko Kawamura ◽  
Yoko Iwata
Keyword(s):  
Life History ◽  
Body Size ◽  
Growth Rates ◽  
Life History Traits ◽  
Environmental Influence ◽  
Life Stage ◽  
Energy Allocation ◽  
Alternative Reproductive Tactics ◽  
Reproductive Tactics ◽  
Somatic Energy

Abstract Squid are characterized by flexible life-history traits (LHTs) that change in response to changing oceanic parameters. Male alternative reproductive tactics (ARTs), characterized by large-sized ‘consorts’ versus small-sized ‘sneakers’, are commonly observed in loliginid species. This study reports on LHTs flexibility in male squids displaying ARTs. LHTs of consorts and sneakers in Uroteuthis edulis, including body size, age, growth rate and gonado-somatic energy allocation, were compared among seasonal and geographical groups from Japan and Taiwan. The ratio of consorts to sneakers was highest in the group spawning in the ‘Japan-warm’ season (June-November), followed by that of the ‘Japan-cold’ season (December-May), and lowest in Taiwan (spring and autumn). LHTs were compared among cohorts separated by hatching season and catch location (Jwarm, Jcold and Taiwan cohorts). Mean body size of consorts showed no difference among cohorts, although Taiwan consorts were relatively younger than Japan consorts. Mean size and age of sneakers decreased with increased water temperature at hatching. Growth rates of consorts and sneakers were slightly different among cohorts, in accordance with differences of statolith increment widths during their early life stage (50-150 d). Growth rates of both consorts and sneakers were highest in the Taiwan cohort, followed by the Jwarm cohort, with the Jcold cohort lowest. Sneakers invested more both in mantle and gonadal weights than consorts in all cohorts. Gonado-somatic energy allocation patterns of consorts and sneakers were consistent at different temperatures. LHTs of U. edulis consorts and sneakers were strongly influenced by temperature, with higher flexibility in sneakers than consorts.

Differential energy allocation of alternative male tactics in masu salmon (Oncorhynchus masou)

2002 ◽  
Vol 59 (11) ◽  
pp. 1717-1723 ◽  
Author(s):  
Yusuke Koseki ◽  
Koji Maekawa
Keyword(s):  
Specific Energy ◽  
Energy Allocation ◽  
Masu Salmon ◽  
Oncorhynchus Masou ◽  
Confounding Effect ◽  
Allocation Pattern ◽  
Mature Parr ◽  
Somatic Energy ◽  
Masu Salmon Oncorhynchus Masou ◽  
Northern Japan

To compare energy allocation to gonad, relative to soma, between alternative male tactics (mature parr and migratory males) in masu salmon (Oncorhynchus masou), we quantified energy contents in somatic and testicular tissues for the two tactics from two lake-run populations (Shikaribetsu Lake and Shumarinai Reservoir) in Hokkaido, northern Japan. Mass-specific testicular energy (kJ·g–1) was lower in migratory males than in mature parr in the Shikaribetsu population, but not in the Shumarinai population. The consistent pattern was observed in somatic energy, suggesting that mass-specific energy reflects population environment rather than inherent allocation pattern. Despite this confounding effect of specific energy, total testicular energy (kJ), relative to total somatic energy, was higher in mature parr in both populations. We suggest that strong sperm competition involved with sneak spawning is responsible for an increased testicular investment in mature parr.

Smart Greedy Distributed Energy Allocation: a Random Games Approach

2021 ◽  
pp. 1-1
Author(s):  
Ilai Bistritz ◽  
Andrew Ward ◽  
Zhengyuan Zhou ◽  
Nicholas Bambos
Keyword(s):  
Energy Allocation ◽  
Distributed Energy ◽  
Random Games

scholarly journals On Energy Allocation and Data Scheduling in Backscatter Networks with Multi-antenna Readers

2021 ◽  
pp. 1-1
Author(s):  
Mohammad Movahednasab ◽  
Mohammad Reza Pakravan ◽  
Behrooz Makki ◽  
Tommy Svensson
Keyword(s):  
Energy Allocation ◽  
Data Scheduling
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