scholarly journals Resource allocation between somatic growth and reproductive output in the pelagic chordate Oikopleura dioica allows opportunistic response to nutritional variation

2002 ◽  
Vol 243 ◽  
pp. 83-91 ◽  
Author(s):  
C Troedsson ◽  
JM Bouquet ◽  
DL Aksnes ◽  
EM Thompson
1993 ◽  
Vol 50 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Andrew R. Lewis ◽  
J. Howard Choat

Reproductive biology of the tropical sepioid cephalopod Idiosepius pygmaeus was investigated in wild specimens and in individuals maintained in aquaria through the adult life span. This species produced multiple egg batches over 80% of the observable adult weight range, indicating a coordination of reproductive and somatic growth. Reproductive output was consistent within, but variable between, individuals. Oocyte synthesis and maturation occur continuously after sexual maturation has been reached. Senescence and death are not related to an exhaustion of reproductive potential. On average, captive female I. pygmaeus with access to unlimited food produced 640 eggs in 11 batches over 18 d. When reproductive output was expressed as a ratio of dry female body weight, on average, specimens had incorporated five times their body weight into eggs and egg coatings. Under food stress, captive specimens laid fewer eggs but maintained egg size and periodicity of egg laying. Food stress had no effect on either laying duration or weight at death. This study provides further evidence that terminal spawning modes are not ubiquitous amongst cephalopods.


1991 ◽  
Vol 48 (2) ◽  
pp. 215-221 ◽  
Author(s):  
B. A. MacDonald ◽  
R. J. Thompson ◽  
N. F. Bourne

Three scallop species from British Columbia display different strategies for partitioning available energy between somatic tissue growth and gamete production as they increase in age. The spiny scallop Chlamys hastata and the pink scallop Chlamys rubida only live about 6 yr and rarely exceed 80 mm in shell height whereas the rock scallop Crassadoma gigantea may reach 170 mm in height and live for 20 yr or more. Growth, reproductive output, and reproductive effort at any given age are higher in Chlamys hastata than in the smaller Chlamys rubida. Somatic growth in Crassadoma gigantea ceases completely in the final years, but in the short-lived species Chlamys hastata and Chlamys rubida, individuals continue to grow until they die. In long-lived pectinids the emphasis often shifts from somatic growth to gamete production before the midpoint of the life cycle, and our observations on Crassadoma gigantea are consistent with this trend. Short-lived species, however, invest relatively less in reproduction; in our study, reproductive output in Chlamys rubida did not exceed 40% of nonrespired assimilation (net production), and reproductive effort in Chlamys hastata did not reach 50% until the final year of life.


2019 ◽  
Vol 42 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Sandra Klintworth ◽  
Eric Von Elert

Abstract Life-history theory predicts that animals adjust their resource allocation to somatic growth or to reproduction to maximize fitness. Resource allocation in Daphnia is known to respond to quantitative food limitation as well as to kairomones released from predators. Here we investigated in a full-factorial design how kairomone from larvae of Chaoborus flavicans, a gape-limited predator, and food quantity (0.5 mg C/L versus 1.5 mg C/L) affect the fatty acid allocation of D. pulex. Low food diminished somatic growth, clutch size and clutch biomass and increased neckteeth formation in response to the kairomone. Low food further led to increased fatty acid amounts per individual egg as well as to increased fatty acid content in eggs and to increased relative fatty acid allocation to reproduction. The latter effect was suppressed by kairomone of Chaoborus, whereas on high food the provision of eggs was further enhanced. We also found that more eicosapentaenoic acid was retained in the body of mothers in the presence of the predator at low food concentrations. These findings indicate that under food limitation and in the presence of kairomone from Chaoborus larvae, Daphnia switches from allocation into current reproduction to investment into future reproductive events.


2020 ◽  
Author(s):  
Wei Zhu ◽  
Liming Chang ◽  
Guocheng Shu ◽  
Bin Wang ◽  
Jianping Jiang

Abstract BackgroundResource allocation trade-off between storage and somatic growth is an essential physiological phenomenon in animals. Revealing its patterns and underlying mechanisms are fundamental for behavior, evolutionary, and population ecological studies. Currently, our understanding of the real-time resource allocating patterns in animals is still limited, and the underlying metabolic mechanisms have been rarely investigated. The life strategy of amphibian larvae relies on precise coordination between storage and somatic growth, which makes them good model for studying this issue.ResultsHere, the resource allocation strategy was investigated for Rana omeimontis tadpoles, who exhibit prominent hepatic fat-accumulation. Results showed that their ontogenetic fat accumulation emerged when tadpoles grew to a body weight range of 30–50 mg, where their fat storage had a high priority in resource allocation. Beyond this range, the resource proportion for somatic growth increased, but continuous storage investment was likely maintained to kept higher body fat index in larger individuals. This seeming paradoxical allocation pattern could be explained by assuming a positive relationship between storage abundance and the investment to somatic growth. This speculation was supported by the observation that storage had the priority in resource allocation to reach a higher body fat index before increment in body weight when food level increased. Moreover, it was also supported by the metabolic pattern that presented lipid-based energy metabolism after ontogenetic fat accumulation, and activating the mobilization of fat storage in the liver can promote the somatic growth. In short, fat synthesis and fat accumulation in the liver may well modulated the resource allocation to somatic growth, and their liver likes a reservoir with valves to regulate energy flow for the downstream developmental processes.ConclusionIn Rana omeimontis tadpoles, their hepatic fat level positively modulated the resource allocation to somatic growth through lipid-based energy metabolism. We reveal the real-time resource allocation pattern in an amphibian tadpole and explain it at molecular level. These results likely provide a new mechanistic insight into the resource allocation in animals.


2018 ◽  
Vol 41 ◽  
Author(s):  
Neil Malhotra

AbstractAlthough Boyer & Petersen's (B&P's) cataloguing of and evolutionary explanations for folk-economic beliefs is important and valuable, the authors fail to connect their theories to existing explanations for why people do not think like economists. For instance, people often have moral intuitions akin to principles of fairness and justice that conflict with utilitarian approaches to resource allocation.


2012 ◽  
Vol 43 (4) ◽  
pp. 232-242 ◽  
Author(s):  
Phia S. Salter ◽  
Glenn Adams

Inspired by “Mother or Wife” African dilemma tales, the present research utilizes a cultural psychology perspective to explore the dynamic, mutual constitution of personal relationship tendencies and cultural-ecological affordances for neoliberal subjectivity and abstracted independence. We administered a resource allocation task in Ghana and the United States to assess the prioritization of conjugal/nuclear relationships over consanguine/kin relationships along three dimensions of sociocultural variation: nation (American and Ghanaian), residence (urban and rural), and church membership (Pentecostal Charismatic and Traditional Western Mission). Results show that tendencies to prioritize nuclear over kin relationships – especially spouses over parents – were greater among participants in the first compared to the second of each pair. Discussion considers issues for a cultural psychology of cultural dynamics.


2018 ◽  
Vol 30 (4) ◽  
pp. 196-206 ◽  
Author(s):  
Byungho Park ◽  
Rachel L. Bailey

Abstract. In an effort to quantify message complexity in such a way that predictions regarding the moment-to-moment cognitive and emotional processing of viewers would be made, Lang and her colleagues devised the coding system information introduced (or ii). This coding system quantifies the number of structural features that are known to consume cognitive resources and considers it in combination with the number of camera changes (cc) in the video, which supply additional cognitive resources owing to their elicitation of an orienting response. This study further validates ii using psychophysiological responses that index cognitive resource allocation and recognition memory. We also pose two novel hypotheses regarding the confluence of controlled and automatic processing and the effect of cognitive overload on enjoyment of messages. Thirty television advertisements were selected from a pool of 172 (all 20 s in length) based on their ii/cc ratio and ratings for their arousing content. Heart rate change over time showed significant deceleration (indicative of increased cognitive resource allocation) for messages with greater ii/cc ratios. Further, recognition memory worsened as ii/cc increased. It was also found that message complexity increases both automatic and controlled allocations to processing, and that the most complex messages may have created a state of cognitive overload, which was received as enjoyable by the participants in this television context.


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