Breeder-Helper Conflict in a Cichlid Fish With Broodcare Helpers: an Experimental Analysis

Behaviour ◽  
1985 ◽  
Vol 95 (1-2) ◽  
pp. 45-75 ◽  
Author(s):  
Michael Taborsky

AbstractThis paper reports an experimental analysis of conflicting interests in the cooperatively breeding Lamprologus brichardi (Cichlidae). Helpers clearly prefer to stay in the family territory rather than leave for an aggregation of same-size young or for an unoccupied area-even when their chances of reproducing independently are superior to those in the field. Helpers usually attain independence when the breeders force them to leave the territory. Breeders' toleration of helpers depends on the stage in the reproductive cycle, the size of helpers and the need for helpers. Large, previously expelled helpers are reaccepted when competition is increased. In these circumstances breeders prefer their own former helpers to strange young. Experimental and field evidence suggests that 3 factors are ultimately important for the breeder/helper relationship: reproductive parasitism by mature helpers, eventual cannibalism on breeders' eggs and competition for shelter within the territory. A graphical model shows how the initially common interests of breeders and helpers develop divergently when helpers reach the size at which they become sexually mature and less susceptible to predation. Large helpers pay to stay. The relationship of breeders and large helpers meets the criterion of reciprocal altruism.

2020 ◽  
Vol 2 (4) ◽  
pp. 126-130
Author(s):  
N. V. SHAMANIN ◽  

The article raises the issue of the relationship of parent-child relationships and professional preferences in pedagogical dynasties. Particular attention is paid to the role of the family in the professional development of the individual. It has been suggested that there is a relationship between parent-child relationships and professional preferences.


2020 ◽  
Vol 4 (4) ◽  
pp. 314
Author(s):  
Ida Rochanawati ◽  
Agusti Efi

Many of Bunda's Tourism Diploma graduates are still unemployed because some are less interested in becoming self-employed. It because students are not motivated to become entrepreneurs, and the family environment is not yet supported. This study aimed to measure: the relationship between entrepreneurial learning outcomes, entrepreneurial motivation, and family environment with interest in entrepreneurship. This type of research is descriptive correlational. This research population is all students of the Hospitality study program of the Bunda Padang Tourism Academy, batch 2017 and 2018, totaling 61 students. The sample in this study were 61 students using the total sampling technique. The data collection instrument used a questionnaire using a Likert scale and data analysis methods, including simple correlation and multiple correlations. Research is expected to increase students' entrepreneurial knowledge through attitudes, knowledge, and skills to overcome entrepreneurial tasks' complexity, providing real experiences for students to carry out entrepreneurial practices.


PEDIATRICS ◽  
1962 ◽  
Vol 29 (4) ◽  
pp. 566-578
Author(s):  
George Bialkin ◽  
Saul Zucker ◽  
Burton S. Sklarin ◽  
Kurt Hirschhorn ◽  
Murray Davidson

A family consisting of a mother and father, heterozygous for idiopathic hyperlipemia, and their four offspring, one heterozygous and three homozygous for the disease, are described. In addition, a fifth child who is heterozygous, born of same mother but by another incompletely studied father, is presented. The genetics of the disease in this family, and also in the general population, with emphasis on diagnosis and prognosis in heterozygotes is discussed. The interrelationship of various lipid components in serum and their metabolism are briefly reviewed. The possible defective mechanisms in hyperlipemia, the techniques for deciding on the specific defect, and their application to the members of this family are reviewed. The effect of heparin, nicotinic acid, and fat-free diets in the homozygous members of the family are evaluated and their therapeutic applications are discussed. The symptomatology, possible pathologic physiology, relationship to lipid levels in serum and occurrence of abdominal crises in some of the homozygous members of this family are pointed out. The relationship of cholesterol and triglyceride levels in serum to, and the significance of, idiopathic hyperlipemia in the genesis of, atherosclerosis and coronary artery disease is elucidated.


1907 ◽  
Vol 13 (4) ◽  
pp. 211-218 ◽  
Author(s):  
EDWIN CHAPIN STARKS

Parasitology ◽  
1965 ◽  
Vol 55 (3) ◽  
pp. 439-451 ◽  
Author(s):  
C. R. Keneedy

Recent experimental work has indicated that species of Archigetes are capable of infecting and maturing in fishes in addition to tubificids.The genus Archigetes is re-defined on the basis of morphological and biological characters, with particular emphasis on recent life history studies. All species capable of neotenic development have been re-united in a single genus.A description of all species of Archigetes together with a key for their identification are included. New synonomies are discussed.The relationship of Archigetes to other genera of the family is briefly considered, and it is concluded that it forms the terminal stage in a series showing the attainment of neotenic development.I wish to thank Professor R. J. Pumphrey in whose Department the work was carried out, and Dr J. C. Chubb for advice and help in the preparation of this manuscript. I am also grateful to Professor K. Berg and Dr R. L. Calentine for the loan of specimens. The work was carried out during the tenure of a Nature Conservancy Research Studentship.


Part I. The Medulla Oblongata, And Its Variations Acoording To Diet And Feeding Habits In previous communications to this Society the relationship of the habits of feeding and diet to the form and pattern of the medulla oblongata has been described in the cyprinoids, clupeids, and gadoids (Evans, 1931, 1932, 1935). This research takes up a similar study of the brain of the Pleuronectidae. The expense has been borne by a grant from the Royal Society for which the author tenders his grateful thanks. It has seemed to be desirable to extend the observations to the fore- and mid-brain, as in some members of the family these present a very marked development. In order to elucidate some of the problems that arise I have also studied the brain of the eel, and some interesting conclusions have resulted. We find, as a result of examination by the naked eye and of serial sections, that we can divide the following species into four groups as follows: I. The sole, Solea vulgaris .


1996 ◽  
Vol 26 (1) ◽  
pp. 25-38 ◽  
Author(s):  
József Gerevich ◽  
Erika Bácskai

The authors examined the relationship of two dimensions of the theory of social development—vulnerability (predictors, risk factors) and protectivity—in two samples, schoolchildren aged ten to fifteen years and addictive drug users. On the basis of the Hirschi model of protective factors, they found that the most important protective factors (attachment, commitment, involvement, belief) act against substance use. A surprising finding was that among the predictors of the addicts some forms of escape from the family act against the development of drug use, that is, they can be regarded as a protective predictor. The findings of the study draw attention to the complexity of the vulnerability-protectivity relationship and to the need for further research.


1959 ◽  
Vol 91 (S10) ◽  
pp. 5-338 ◽  
Author(s):  
Margaret Rae MacKay

AbstractThe late-instar larvae of about 185 species of the North American Olethreutidae are described and most of them illustrated. Included in these are many pests, such as Grapholitha molesta, Carpocapsa pomonella, and Spilonota ocellana on fruit trees, Paralobesia viteana on grapes, Ancylis comptana fragariae on strawberries, Laspeyresia nigricana in pea pods, Laspeyresia caryana in hickory and pecan nuts, Taniva albolineana in spruce needles, and species of Rhyacionia and Petrova on pines. Keys to species groups and to individual species are provided. Of the diagnostic and specialized characters listed, the most useful include the setae, the spinneret, and the shape of the larva, especially of its head and anal shield. The main characters are given for the postulated ancestral larva and for the highly developed larva. Most of the species groups are arranged according to the suggested phylogenetic relationship of their larvae, emphasizing the necessity of a revision of the family. Larvae of some genera previously difficult to classify, such as Pseudogalleria and Hystricophora, indicate the relationship of those genera to other groups; conversely, lack of relationship is clearly shown in other instances, e.g., between Carpocapsa pomonella and Carpocapsa saltitans, and between the two species Epiblema culminana and E. suffusana and other members of the genus Epiblema.


2010 ◽  
Vol 84 (6) ◽  
pp. 1135-1151 ◽  
Author(s):  
John R. Bolt ◽  
R. Eric Lombard

A new colosteid, Deltaherpeton hiemstrae gen. et sp. nov., is described from the Mississippian Upper Viséan site at Delta, Iowa. Deltaherpeton is represented by a skull roof and both jaws. The new taxon is unique among colosteids in having an internasal and single midline postparietal. An additional midline pair of cf. ‘interfrontonasals’ may be present. Characters previously used to define the colosteids are reviewed and a refined diagnosis for the family Colosteidae is presented. Synapomorphies which unite Deltaherpeton, Colosteus, Greererpeton, and Pholidogaster as Colosteidae are: premaxilla with fang pair; dentary with notch for receipt of premaxillary fang; mandible with single elongate exomeckelian fenestra; pre-narial infraorbital lateral line terminating at ventral margin of premaxilla just anterior to external naris; and post-narial infraorbital lateral line terminating at the ventral margin of the maxilla just posterior to the external naris. Our review of dermal bones in the colosteid snout concludes that no specimen is sufficiently free of distortions or breakage to indicate clearly whether or not the prefrontal borders the external naris, or that an anterior tectal is present. The morphology of Deltaherpeton and the revised data presented for colosteids do not clarify the relationship of colosteids to other early tetrapods.


1997 ◽  
Vol 10 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Drew S. Mendoza ◽  
Sharon P. Krone

A business-owning family and a soon-to-be-wed couple often face two mutually exclusive goals that seem impossible to reconcile. On the one hand, a couple considering marriage wants to believe that love alone will keep them together. On the other hand, statistics today say there is a good chance the relationship will not last. A prenuptial agreement provides the protection an individual or the family may want against a possible divorce, but the process by which the document is introduced and negotiated can deplete the relationship of intimacy. How can a woman from a wealthy business-owning family express and reinforce the emotional commitment and trust she has for her partner while presenting a prenuptial agreement] How can a son administer a prenuptial agreement to his fiancee without controlling the process or outcome of his spouse's financial welfare] How can a family require a prenuptial agreement without jeopardizing their future relationship with the newlyweds] In the following interview, Judy Barber, a consultant and licensed marriage and family counselor specializing in the psychology of money, outlines several recommendations for families and couples who are considering a prenuptial agreement.


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