Life History and Abundance of Mysis relicta in Lake Michigan

1978 ◽  
Vol 35 (9) ◽  
pp. 1165-1170 ◽  
Author(s):  
Mark D. Morgan ◽  
Alfred M. Beeton
Keyword(s):  
Life History ◽  
Key Words ◽  
Lake Michigan ◽  
Fourth Instar ◽  
Mysis Relicta ◽  
First Instar ◽  
Males And Females

Mysis relicta was sampled in Lake Michigan approximately monthly with an epibenthic sled, August 1975–July 1976. Total numbers ranged from a low of 23 m−2 in February to a high of 337 m−2 in May and averaged 188 m−2. It was possible to partition the population into five instars. Major peaks in proportions of first instar individuals occurred in March, July, and November. It took about 1 yr for first instar individuals to reach the fourth instar. Growth averaged a little less than 1 mm/mo. Males and females reached maturity and bred in the fourth instar, so females produced their first brood at 1 yr of age. Males died at this time, but females were found to molt to the fifth instar, mate, and produce a second brood approximately 4 mo later. Key words: Mysis relicta, Lake Michigan, life history, abundance

Growth and development of larvae and adults of Tipula sacra Alexander (Insecta: Diptera) in a series of abandoned beaver ponds

1976 ◽  
Vol 54 (2) ◽  
pp. 266-284 ◽  
Author(s):  
G. Pritchard
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Growth And Development ◽  
Adult Emergence ◽  
Head Capsule ◽  
Fourth Instar ◽  
Beaver Ponds ◽  
The Third ◽  
First Instar ◽  
Two Peaks

Collections of all stages of the crane fly, Tipula sacra have been made over a period of years from a series of abandoned beaver ponds in the Kananaskis Valley, Alberta. The growth of larvae was followed by head-capsule measurements and weights. Eggs hatch within a month; first-instar larvae grow rapidly and enter the second instar after a few weeks. The second instar may last for 3 months and the third instar usually lasts for 6 months, including the first winter. Most larvae spend almost a full year in the fourth instar and overwinter for a second time. However, there was much variation in growth rate within the population. Adult emergence curves were consistent in form in 4 years. Each spanned a period of just over 2 months, although individual adults lived for only a few days. These curves snowed two peaks, the second of which contained 15–20% of the year's emergents. These two groups may represent different cohorts that have grown at different rates, suggesting that the life history may be semivoltine or univoltine. The sex ratio changes from about 1:1 in the third instar to 2:1 in favor of males in the late fourth instar, pupa, and adult.

Density Estimates of Mysis relicta in Lake Michigan

1979 ◽  
Vol 36 (6) ◽  
pp. 694-698 ◽  
Author(s):  
Nevin E. Grossnickle ◽  
Mark D. Morgan
Keyword(s):  
Key Words ◽  
Lake Michigan ◽  
Density Estimates ◽  
Mysis Relicta ◽  
Deep Station ◽  
Late Instar ◽  
Order Of Magnitude

Density estimates of Mysis relicta based on night vertical net tows at stations of 30–50 m in Lake Michigan were about an order of magnitude larger than previous estimates based on sled tows. Significantly greater density estimates were obtained in night vertical net tows than those collected before sunset at these shallow stations. However, density estimates based on sled tows during daylight were not significantly different from those based on night vertical net tows at a 115-m station in Lake Michigan. At this deep station, a substantially larger percentage of late instar mysids was collected in sled tows than in night vertical net tows. Key words: Mysis relicta, Lake Michigan, density estimates, vertical net tows, epibenthic sled tows

Life history, gonad state, and changes in functional sex ratio in the salt-marsh waterboatman, Trichocorixa verticalis (Fieber) (Heteroptera: Corixidae)

1995 ◽  
Vol 73 (3) ◽  
pp. 552-556 ◽  
Author(s):  
R. B. Aiken ◽  
N. Malatestinic
Keyword(s):  
Life History ◽  
Salt Marsh ◽  
Sex Ratio ◽  
Sexual Development ◽  
Mate Competition ◽  
Summer Generation ◽  
First Instar ◽  
Males And Females ◽  
Marsh Pools ◽  
Sexually Mature

The life history and sexual development of Trichocorixa verticalis were studied in salt-marsh pools in New Brunswick, Canada. Trichocorixa verticalis overwinters as an egg and the adults of the first summer generation appear in late June. The second summer generation appears as first-instar nymphs in mid-July. Males and females mature sexually about 1 month after eclosion, the first sexually mature females appearing 1 week before males. For most of the season, the numerical sex ratio is male-biased. The functional sex ratio (ratio of sexually mature males and females) is even more strongly male-biased. These results indicate that mate competition among males may be more severe than was initially apparent.

Feeding-Behavior Repertoire of the Alewife, Alosa pseudoharengus, and the Ciscoes Coregonus hoyi and C. artedii

1978 ◽  
Vol 35 (2) ◽  
pp. 249-253 ◽  
Author(s):  
John Janssen
Keyword(s):  
Great Lakes ◽  
Feeding Behavior ◽  
Key Words ◽  
Lake Michigan ◽  
Alosa Pseudoharengus ◽  
Calanoid Copepods ◽  
Mysis Relicta ◽  
Particulate Feeding ◽  
Coregonus Hoyi

Particulate feeding, where fish orient to and take prey one at a time, is shown by the alewife, Alosa pseudoharengus, and the ciscoes Coregonus hoyi and C. artedii. Specialized particulate feeding is found in ciscoes and alewives for capturing strongly swimming prey such as Mysis relicta and calanoid copepods. This involves simultaneous darting and sucking. Alewives filter feed by swimming with the mouth fully agape for 0.5–2 s while driving hard with the tail. Ciscoes do not filter feed, but they and alewives display gulping behavior where fish open and close the mouth 2–3 times/s, do not drive hard with the tail, and may take more than one prey per gulp. The alewife has difficulty feeding near or on the bottom. The ciscoes feed easily on or near the bottom and will also take buried prey. Key words: Alosa pseudoharengus, Coregonus hoyi, C. artedii, feeding behavior, Great Lakes, Lake Michigan

Comparison of egg size and related life-history characteristics for two predaceous tree-hole mosquitoes (Toxorhynchites)

1980 ◽  
Vol 58 (11) ◽  
pp. 2065-2070 ◽  
Author(s):  
R. J. Lamb ◽  
S. M. Smith
Keyword(s):  
Life History ◽  
Egg Size ◽  
Prey Size ◽  
Prey Availability ◽  
Fourth Instar ◽  
Natural Environments ◽  
First Instar ◽  
Life History Characteristics ◽  
Tree Hole ◽  
Toxorhynchites Rutilus

Certain life-history characteristics of Toxorhynchites brevipalpis and Tx. rutilus septentrionalis were compared in the laboratory with the aim of accounting for a more than twofold difference in the weight of their eggs. First- and second-instar larvae of Tx. rutilus were longer and third-instar larvae shorter than corresponding stages of Tx. brevipalpis. The sizes of the two species did not differ appreciably in the later stages. Toxorhynchites rutilus first-instar larvae consumed more prey but total prey consumption was much greater for Tx. brevipalpis due to differences in consumption during the fourth instar. Developmental times from egg to adult did not differ at 25 °C. Toxorhynchites brevipalpis produced twice as many eggs per day during the first 14 days of oviposition but, due to size differences, the weight of the eggs produced per day was equal for the two species. Female Tx. brevipalpis laid an average of 5.9 eggs per oviposition flight. A corresponding value for Tx. rutilus was not determined. Newly hatched Tx. brevipalpis larvae withstood starvation for a longer period of time than Tx. rutilus larvae. Larval Tx. rutilus captured and consumed larger prey.It is hypothesized that egg size and fecundity are adapted to prey size and heterogeneity in prey availability in the natural environments of the two species.

Life History Traits in a Population of Pelobates syriacus (Boettger, 1889) from Turkey

2020 ◽  
Vol 27 (4) ◽  
pp. 195-200
Author(s):  
Ufuk Bülbül ◽  
Halime Koç ◽  
Yasemin Odabaş ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
...  
Keyword(s):  
Life History ◽  
Age Structure ◽  
Life History Traits ◽  
Spadefoot Toad ◽  
Males And Females

Age structure of the eastern spadefoot toad, Pelobates syriacus from the Kızılırmak Delta (Turkey) were assessed using phalangeal skeletochronology. Snout-vent length (SVL) ranged from 42.05 to 86.63 mm in males and 34.03 to 53.27 mm in females. Age of adults ranged from 2 to 8 years in males and 3 to 5 years in females. For both sexes, SVL was significantly correlated with age. Males and females of the toads reached maturity at 2 years of age.

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.

A field study of competition and interaction between Lemna minor and Lemna trisulca

1989 ◽  
Vol 67 (10) ◽  
pp. 2904-2911 ◽  
Author(s):  
Alexander L. McIlraith ◽  
Gordon G. C. Robinson ◽  
Jennifer M. Shay
Keyword(s):  
Life History ◽  
Field Study ◽  
Key Words ◽  
Field Experiments ◽  
Lemna Minor ◽  
Survey Methods ◽  
The Other ◽  
Transplant Experiment ◽  
Replacement Series ◽  
Vegetative Biomass

Field experiments and survey methods were used to assess competition and interaction between Lemna minor L. and Lemna trisulca L. at Delta Marsh, Manitoba. Sites were dominated by one or the other species or codominated by both. Replacement series experiments predicted codominance of L. minor and L. trisulca in an unshaded eutrophic site but predicted L. minor dominance when run for a longer time. Similar experiments conducted in a shaded eutrophic site predicted L. minor dominance. Addition series experiments showed that intraspecific and interspecific competition occurred in the unshaded site. In a eutrophic unshaded ditch, high densities of L. minor suppressed L. trisulca. In a eutrophic shaded site, high densities of L. minor and green algae inhibited L. trisulca, and in a sunny, less eutrophic site high density of each species inhibited the other. In a transplant experiment, L. minor biomass in shaded enclosures approached that found naturally in two shaded sites. Lemna trisulca persisted when shaded. Vegetative biomass trends in an unshaded eutrophic marsh ditch indicated spring and fall L. trisulca dominance and summer L. minor dominance. Shaded eutrophic sites were dominated by L. minor, whereas a less eutrophic site was dominated by L. trisulca. A model is developed to explain dominance patterns, and seasonal life-history responses are considered. Key words: Lemna, duckweed, competition, interaction, resources, light, nutrients.

Early life history of alewife Alosa pseudoharengus in southwestern Lake Michigan

2015 ◽  
Vol 41 (2) ◽  
pp. 436-447 ◽  
Author(s):  
Michael J. Weber ◽  
Blake C. Ruebush ◽  
Sara M. Creque ◽  
Rebecca A. Redman ◽  
Sergiusz J. Czesny ◽  
...  
Keyword(s):  
Life History ◽  
Early Life ◽  
Lake Michigan ◽  
Early Life History ◽  
Alosa Pseudoharengus ◽  
History Of
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