The life history and distribution of Neomysis americana (Smith) (Crustacea, Mysidacea) in Passamaquoddy Bay

1979 ◽  
Vol 57 (4) ◽  
pp. 785-793 ◽  
Author(s):  
D. S. Pezzack ◽  
S. Corey

Neomysis americana in Passamaquoddy Bay produces two generations per year. Breeding occurs during the spring, summer, and early fall. Each female is capable of producing two or three broods; average brood sizes for spring and summer females were 45 and 32, respectively. Development time of eggs varied directly with temperature. The intermolt period of juveniles remained constant up to the time of the development of secondary sexual characteristics, between the eighth and ninth molts, and then increased. The life history of N. americana in Passamaquoddy Bay is compared with that in other areas.

Parasitology ◽  
1927 ◽  
Vol 19 (1) ◽  
pp. 86-99 ◽  
Author(s):  
F. J. Brown

1. Crepidostomum farionis inhabits the gall bladder, as well as the intestine and pyloric caeca, of the trout and grayling.2. The life history of Crepidostomum farionis has been worked out and is based on the similarity of organisation of the cercaria, encysted larval trematode and the adult.3. The first intermediate hosts in the life history of this trematode are Pisidium amnicum (Müll.) and Sphaerium corneum (L.) though the latter is unusual.4. The second intermediate host is the larva of the mayfly, Ephemera danica (Müll.).5. There are two generations of rediae, the first gives rise to daughter rediae, which in turn produce cercariae.6. The rediae are characterised by the absence of ambulatory processes and a functional intestine.7. The cercaria (n.sp.) possesses “eye spots,” stylet and gland cells (salivary?), and the excretory vesicle is tube-shaped.8. The excretory system of the redia and the cercaria has been worked out in detail.9. The relation of the parasites to their respective hosts is discussed. On account of the need for further observations definite conclusions are held over for a later paper.


1898 ◽  
Vol 63 (389-400) ◽  
pp. 56-61

The two most important deviations from the normal life-history of ferns, apogamy and apospory, are of interest in themselves, but acquire a more general importance from the possibility that their study may throw light on the nature of alternation of generations in archegoniate plants. They have been considered from this point of view Pringsheim, and by those who, following him, regard the two generations as homologous with one another in the sense that the sporophyte arose by the gradual modification of individuals originally resemblin the sexual plant. Celakovsky and Bower, on the other hand, maintaint the view tha t the sporophyte, as an interpolated stage in the life-history arising by elaboration of the zygote, a few thallophytes.


2016 ◽  
Vol 8 (3) ◽  
pp. 77
Author(s):  
Geraud Canis Tasse Taboue ◽  
Eric Bertrand Fokam

Frogs of the genus <em>Phrynobatrachus </em>Günther, 1862 are endemic to sub-Saharan Africa. These are increasingly threatened by a number of factors and are believed to be declining. We report on captive breeding experiments involving <em>Phrynobatrachus auritus</em> Boulenger, 1900. We provide a comprehensive life history for this frog with emphasize on tadpole development time, as well as a description of both the advertisement call and calling behaviour of the adult.


1975 ◽  
Vol 53 (7) ◽  
pp. 942-952 ◽  
Author(s):  
T. Amaratunga ◽  
S. Corey

A 17-month field study showed that Mysis stenolepis in Passamaquoddy Bay, New Brunswick lives for about 1 year. Young are released in shallow water early in spring and grow rapidly during the summer. In the fall, young adults migrate to deeper water where they reach sexual maturity. Transfer of sperm lakes place during winter in deeper regions of the Bay. soon after which the males die. Females survive and in spring migrate to shallow waters to release young after which they die. Females breed once and carry an average of 157 young per brood. Developmental stages of the postmarsupial young are described and discussed.


1976 ◽  
Vol 54 (5) ◽  
pp. 615-619 ◽  
Author(s):  
Susan Corey

Diastylis sculpta was collected from shallow water (1–15 m) in Passamaquoddy Bay over a 26-month period. D. sculpta produces a rapidly growing and developing summer generation between two successive winter generations. The overwintering generation releases young in mid-July and late August. The summer generation releases young in November. The mean fecundity of the summer-gravid females (78.4) is much greater than the mean fecundity (20.0) of the fall-gravid females. The maximum life-span is 5 months and 12 months for members of the summer and winter generations respectively.


1974 ◽  
Vol 52 (4) ◽  
pp. 495-505 ◽  
Author(s):  
K. W. Hollingshead ◽  
S. Corey

Monthly collections of Meganyctiphanes norvegica for a 19-monih period in Passamaquoddy Bay showed that these euphausiids were present in the bay in varying numbers from February to November but virtually disappeared in December and January. Sexual maturity is attained in 1 year with gonadal development taking 3 months, and spawning occurring in July and August. The resulting generation will breed and spawn for the first time the next July as age group I. Age group I grows from April until August; from September until March, very little growth occurs. After a second breeding and spawning, the animals die, having a life span of 2 years.


1978 ◽  
Vol 56 (3) ◽  
pp. 492-506 ◽  
Author(s):  
David W. Kulka ◽  
S. Corey

A 4-year study of the life history of Thysanoessa inermis was conducted in Passamaquoddy Bay. A comparison of the growth pattern and eye morphology showed that Th. inermis in Passamaquoddy Bay is part of a Bay of Fundy population centered in the Grand Manan Basin. Spawning occurs in the spring and the young stages are found near the surface during the summer. Thysanoessa inermis lives for 2 years in the Bay of Fundy and spawns at the end of the 1st and 2nd years. Gonadal development is described in detail. Growth in both years is rapid during the summer months with little or no increase in size during the winter. The growth rate of the female surpasses that of the males in the 2nd year. The neglecta form of Th. inermis (year class 0 animals) lives in the middle to upper layers and is morphologically different from the inermis form (year class I animals) which lives in the deepest layers.


2018 ◽  
Author(s):  
Joseph B. Deas ◽  
Leo Blondel ◽  
Cassandra G. Extavour

ABSTRACTAncestral environmental conditions can impact descendant phenotypes through a variety of epigenetic mechanisms. Previous studies on transgenerational effects in Drosophila melanogaster suggest that parental nutrition may affect the body size, developmental duration, and egg size of the next generation. However, it is unknown whether these effects on phenotype remain stable across generations, or if specific generations have general responses to ancestral diet. In the current study, we examined the effect on multiple life history phenotypes of changing diet quality across three generations. Our analysis revealed unforeseen patterns in how phenotypes respond to dietary restriction. Our generalized linear model showed that when considering only two generations, offspring phenotypes were primarily affected by their own diet, and to a lesser extent by the diet of their parents or the interaction between the two generations. Surprisingly, however, when considering three generations, offspring phenotypes were primarily impacted by their grandparents’ diet and their own diet. Interactions amongst different generations’ diets affected development time, egg volume, and pupal mass more than ovariole number or wing length. Further, pairwise comparisons of diet groups from the same generation revealed commonalities in strong responses to rich vs. poor diet: ovariole number, pupal mass, and wing length responded more strongly to poor diet than to rich diet, while development time responded strongly to both rich and poor diets. To improve investigations into the mechanisms and consequences of transgenerational, epigenetic inheritance, future studies should closely examine how phenotypes change across a higher number of generations, and consider responses to broader variability in diet treatments.


Marilyn Bailey Ogilvie, Women in science, antiquity through the nineteenth century . Cambridge, Massachusetts: MIT Press, 1986. Pp. xi 4- 254, £24.75. ISBN 0-262-15031-X Margaret Alic, Hypatia's heritage: a history of women in science from antiquity to the late nineteenth century . London: The Women’s Press, 1986. Pp. ix + 230, £4.95. ISBN 0-7043-3954-4 Londa Schiebinger, The mind has no sex? Women in the origins of modem science . Cambridge, Massachusetts: Harvard University Press, 1989. Pp. xi + 355, £23.50. ISBN 0-674-57623-3 Patricia Phillips, The scientific lady: a social history of woman's scientific interests 1520-1918 . London: Weidenfeld and Nicolson, 1990. Pp. xiii + 279, £25.00. ISBN 0-297-82043-5 Uneasy careers and intimate lives: women in science, 1789-1979 . Edited by Pnina G. Abir-Am & Dorinda Outram. New Brunswick: Rutgers University Press, 1987. Pp. xiii + 365, £11.00. ISBN 0-8135-1255-7 Women of science: righting the record . Edited by G. Kass-Simon & Patricia Fames. Bloomington, Indiana: Indiana University Press, 1990. Pp. xvi + 398, $39.95. ISBN 0-253-33264-8 Not long ago women were largely absent from the histories of science, even from social histories of science. With the 1960s came the questions: where were the women? how to do them justice? were there so few? why so few? Several books have now addressed these difficult questions. Charles Darwin gave an answer to the last question, by including ‘the intellectual powers of the sexes’ with the secondary sexual characteristics discussed in The descent of man, and selection in relation to sex .


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