Life History of Lepeophtheirus salmonis

1942 ◽  
Vol 6a (1) ◽  
pp. 24-29 ◽  
Author(s):  
H. C. White
Keyword(s):  
Life History ◽  
Salmo Salar ◽  
Developmental Stages ◽  
Salvelinus Fontinalis ◽  
Lepeophtheirus Salmonis ◽  
History Of ◽  
Males And Females

Heavy infestations of this copepod in various developmental stages occur on Salmo salar and Salvelinus fontinalis at Moser River, N.S. Males and females occur in about equal numbers. Metanauplius and chalimus stages were present on the fins of the hosts. The male and four of the developmental stages are described and figures given. The parasite feeds on the skin of its host.

BIOLOGY OF TACHINAEPHAGUS ZEALANDICUS (HYMENOPTERA: ENCYRTIDAE), PARASITOID OF SYNANTHROPIC DIPTERA

1974 ◽  
Vol 106 (8) ◽  
pp. 785-800 ◽  
Author(s):  
G. S. Olton ◽  
E. F. Legner
Keyword(s):  
Life History ◽  
Developmental Stages ◽  
Average Length ◽  
Host Density ◽  
Adult Emergence ◽  
Reproductive Period ◽  
Laboratory Studies ◽  
Pupal Parasitoid ◽  
History Of ◽  
Parasitoid Development

AbstractThe synonymy, distribution, host range, and life history of the gregarious larval–pupal parasitoid Tachinaephagus zealandicus Ashmead, is discussed. Laboratory studies of its biology were conducted at 25° ± 2 °C using Musca domestica L. as host. Its developmental stages are described. Under laboratory conditions its life cycle lasted 23–27 days. Parasitoid development accelerated with higher average densities per host. Single standardized hosts produced 3–18 adult parasitoids. Mated females provided with hosts lived 50.4–67.2 h. The average length of the reproductive period and number of hosts parasitized were independent of host density; however, the average number of eggs deposited per host increased at lower host densities. Adult emergence displayed circadian rhythmicity independent of photoperiod over 3+ days.

The Life History and Habits of Chrysomela crotchi Brown (Coleoptera: Chrysomelidae) in Northwestern Ontario

1965 ◽  
Vol 97 (5) ◽  
pp. 541-549 ◽  
Author(s):  
E. P. Smereka
Keyword(s):  
Life History ◽  
Adult Stage ◽  
Egg Mass ◽  
Predator Species ◽  
Control Factors ◽  
Northwestern Ontario ◽  
History Of ◽  
Males And Females ◽  
Overwintering Mortality ◽  
Larval Parasites

AbstractThe life history of Chrysomela crotchi, a univoltine species commonly found on trembling aspen, was studied in northwestern Ontario from 1959 to 1962. The most striking feature of its life history was the longevity of adults, which were capable of overwintering two successive years. Overwintered adults became active and began feeding in late May, and oviposition occurred from early June to late July. The incubation period was approximately 10 days and the three larval instars required approximately one month for development to the adult stage.Females laid more eggs during their second season and the highest number laid was 326. The number of eggs in an egg mass averaged 37.6, and the average interval between the deposition of egg masses was 4 days. Males and females mated more than once, but only one mating was necessary for a female to produce viable eggs throughout the season. Males were capable of fertilizing more than one female and remained potent for more than one season.Parasitism was low, and only two species of larval parasites were reared. Several predator species were observed preying on the immature stages. Predation and overwintering mortality appeared to be the most important control factors.

Life history of Mysis stenolepis Smith (Crustacea, Mysidacea)

1975 ◽  
Vol 53 (7) ◽  
pp. 942-952 ◽  
Author(s):  
T. Amaratunga ◽  
S. Corey
Keyword(s):  
Young Adults ◽  
Life History ◽  
New Brunswick ◽  
Shallow Water ◽  
Field Study ◽  
Sexual Maturity ◽  
Developmental Stages ◽  
Shallow Waters ◽  
Passamaquoddy Bay ◽  
History Of

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.

scholarly journals V. On the early development of cirripedia

1894 ◽  
Vol 185 ◽  
pp. 119-232 ◽  
Keyword(s):  
Life History ◽  
Early Development ◽  
Developmental Stages ◽  
Short Stay ◽  
Complete Understanding ◽  
Cambridge University ◽  
Modern Methods ◽  
History Of ◽  
Complete Series ◽  
The Subject

During a short stay at Plymouth, in 1889, I was engaged in studying certain points in the anatomy of Cirripedia; finding, however, that a knowledge of the embryology was necessary in order to arrive at a complete understanding of the adult structure, I became wishful to investigate the life-history of some one member of the group. This I had an opportunity of doing at Naples, where I was appointed to occupy the Cambridge University Table at the Zoological Station for a period of six months, subsequently increased to nine. I here succeeded in obtaining a practically complete series of stages of Balanus perforatus , Bruguiere, as well as many stages in other members of the group. Though a number of able observers have occupied themselves with the embryology of Cirripedes, yet, owing to lack of opportunity, and to the difficulty of obtaining complete series of developmental stages, as well' as to the inherent difficulties in the subject, much remained to be done in this line. Willemoes-Suhm alone, with the advantages afforded by his position during the Challenger Expedition, has hitherto obtained a complete series of stages of any one form, but he failed to trace the history of the earlier stages, and in the later, limited himself to the appearance of fresh and spirit specimens, as seen without cutting sections. In fact the method of sections has been little applied to the development of Cirripedes, and not at all to the earlier stages. There is, therefore, little apology needed for an account embracing the results obtained by the employment of some of the more modern methods of embryological study.

Maturation, reproduction and early life history of anglerfish Lophius piscatorius in Faroese waters

2015 ◽  
Vol 60 ◽  
pp. 114 ◽  
Author(s):  
Lise H. Ofstad ◽  
Torstein Petersen ◽  
Petur Steingrund
Keyword(s):  
Life History ◽  
Early Life ◽  
Early Life History ◽  
Nursery Ground ◽  
Life Stages ◽  
Morphological Transformation ◽  
Spawning Areas ◽  
History Of ◽  
Males And Females ◽  
First Maturity

<p>Maturation, reproduction and early life history of <em>Lophius piscatorius </em>was investigated in Faroese waters. Length at first maturity (L50) was 58 cm for males and 84 cm for females, corresponding to an age of about four years for males and seven years for females. The proportions of females and males were similar in fish less than 55 cm long, and were skewed towards more males in medium sized fish (55–75  cm).  Females  were  predominant  in the larger fish (&gt; 85 cm). Observations of spawning males and females, egg ribbons and pelagic anglerfish larvae, suggest that the main spawning season is from February to April and the spawning area seems to be southwest of the Faroe Plateau and in the Faroe Bank area. The Faroe Plateau probably serves as a nursery ground for juvenile anglerfish. Morphological transformation from larvae to juveniles occurred when the fish were about 7–9 cm long and they settled to the bottom when they were about 11 cm long. Thus, all life stages, as well as nursery areas, spawning areas and feeding areas of anglerfish are found in Faroese waters, indicating a separate stock in the area.</p>

scholarly journals Life-History of the Salmon (Salmo salar L.)

Nature ◽  
1938 ◽  
Vol 141 (3579) ◽  
pp. 1017-1017 ◽  
Author(s):  
J. H. ORTON ◽  
J. W. JONES
Keyword(s):  
Life History ◽  
Salmo Salar ◽  
History Of

Life History of Sea-Running Brook Trout (Salvelinus fontinalis) of Moser River, N.S.

1940 ◽  
Vol 5a (2) ◽  
pp. 176-186 ◽  
Author(s):  
H. C. White
Keyword(s):  
Life History ◽  
Fresh Water ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Large Fish ◽  
History Of

Smolts, kelts and non-mature large fish descend in May and early June to the sea, to remain feeding in the estuary or near the shore. They began (1939) to ascend the river in late June, and 93% of the "run" was in July.Fish marked when descending one branch of the river ascended both that branch and the river above but the proportion of marked fish was greater in the branch.These trout agree with the local salmon in having smolts that become silvery before migration and that are two or three years old. Trout smolts and kelts remain in the sea only about two months before returning to fresh water.

Studies on Effects of Forest Sprayings with Insecticides, 1952–63, on Fish and Aquatic Invertebrates in New Brunswick Streams: Introduction and Summary

1967 ◽  
Vol 24 (4) ◽  
pp. 701-708 ◽  
Author(s):  
C. J. Kerswill
Keyword(s):  
New Brunswick ◽  
Salmo Salar ◽  
Aquatic Invertebrates ◽  
Salvelinus Fontinalis ◽  
Feeding Habits ◽  
Choristoneura Fumiferana ◽  
Aquatic Insect ◽  
Management Program ◽  
Laboratory Studies ◽  
History Of

This introduces a series of papers on fisheries studies associated with operational and experimental forest spraying, mainly with DDT-in-oil insecticide. It outlines: (a) the history of the spray program developed to counteract an outbreak of the spruce budworm (Choristoneura fumiferana) in New Brunswick; (b) administrative arrangements for developing and coordinating a reasonable research and management program concerning the affected fisheries, mainly for Atlantic salmon (Salmo salar); (c) highlights of field and laboratory studies on effects of insecticide sprayings on caged young salmon and trout (Salvelinus fontinalis), on aquatic insect production, on feeding habits of native young salmon, and on population levels of young salmon.

scholarly journals Ancient androdioecy in the freshwater crustacean Eulimnadia

2005 ◽  
Vol 273 (1587) ◽  
pp. 725-734 ◽  
Author(s):  
Stephen C Weeks ◽  
Thomas F Sanderson ◽  
Sadie K Reed ◽  
Magdalena Zofkova ◽  
Brenton Knott ◽  
...  
Keyword(s):  
Life History ◽  
Mating System ◽  
Breeding System ◽  
Living Systems ◽  
System Evolution ◽  
Mating System Evolution ◽  
History Of ◽  
Freshwater Crustacean ◽  
Males And Females

Among the variety of reproductive mechanisms exhibited by living systems, one permutation—androdioecy (mixtures of males and hermaphrodites)—is distinguished by its rarity. Models of mating system evolution predict that androdioecy should be a brief stage between hermaphroditism and dioecy (separate males and females), or vice versa. Herein we report evidence of widespread and ancient androdioecy in crustaceans in the genus Eulimnadia , based on observations of over 33 000 shrimp from 36 locations from every continent except Antarctica. Using phylogenetic, biogeographical and palaeontological evidence, we infer that androdioecy in Eulimnadia has persisted for 24–180 million years and has been maintained through multiple speciation events. These results suggest that androdioecy is a highly successful aspect of the life history of these freshwater crustaceans, and has persisted for orders of magnitude longer than predicted by current models of this rare breeding system.

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