GBIC Materials Available at Jack K. Williams Library
Permanent URI for this collectionhttps://hdl.handle.net/1969.3/28657
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Browsing GBIC Materials Available at Jack K. Williams Library by Subject "Acartia tonsa"
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Item Influence of natural particle diets on egg laying and hatching success of Acartia tonsa in East Lagoon, Galveston, Texas.(Texas A&M University., 1982) Ambler, J.W.;Factors affecting egg production and hatching success of the copepod Acartia tonsa Dana were determined by measuring environmental variables and daily egg production of field collected females in the laboratory. During five periods between April and November of 1981, three day experiments were run at ambient particle concentrations and two dilutions of 1) natural particles collected over the water column, and 2) some modification of 1). Other A. tonsa were fed Thalassiosira weissflogii to isolate the effects of temperature and salinity on egg production.Item A laboratory method for the culture of Acartia tonsa (crustacea: copepoda) using rice bran(1982) Turk, P.E.; Krejci, M.E.; Yang, W.T.; Journal of Aquariculture and Aquatic SciencesThe calanoid copepod Acartia tonsa was cultured in rectangular tanks filled with 170L of natural sea water. Rice bran added to the culture water provided all the nutrient enrichment necessary to raise A. tonsa throughout its life cycle, thus eliminating the need for separately cultured phytoplankton. Four, month-long preliminary experiments produced maximum densities of copepodid stages including adults that ranged from 170 to 1,520 per L (x=679 per L). The time required to reach maximum density ranged from 6 to 33 days for nauplii and from 12 to 27 days for copepodid stages. The results are preliminary in nature but indicate future potential of this technique as a simple, inexpensive method for the mass culture of copepods.Item The movements of a marine copepod in a tidal lagoon.(1979) Show, I.T., Jr.; Hamilton, P. and K.B. Macdonald; Estuarine and wetland processes: with emphasis on modeling.It has been hypothesized that marine copepods are able to react to water movements in an estuary in such a way as to minimize advective losses to the open ocean. The model is used to describe the movements of Acratia tonsa (Copepoda) in a tidal lagoon on the eastern end of Galveston Island, Texas. Four distinct processes are considered: advection by currents, behavioural response to environmental variables, intraspecific aggragation, and birth-death processes. The biological model is driven by a three- dimensional physical dynamic model which provides numerical solutions for current velocity, temperature, and salinity fields.Item A spatial modeling approach to pelagic ecosystems.(Texas A&M University., 1977) Show, I.T., Jr.;A modeling technique is developed and applied to two different marine ecosystems problems. The technique approaches marine systems through the mathematical modeling of spatial patterns and deals with spatial heterogeneity in marine zooplankton and environmental parameters. In one instance, the spatial distribution of the copepod, Acartia tonsa, in East Lagoon, Galveston Island, Texas is modeled. The East Lagoon model is driven by a dynamic three-dimensional physical numeric model which provides current velocity, temperature, and salinity feilds. The biological model uses these fields to determine the spatial patterns of A. tonsa in terms of its response to current velocity fields, behavioral responses to temperature and salinity gradients, intranspecific aggregation, and birth-death processes. The model yields stochastic means and variances. The results are shown to closely approximate field data from East Lagoon. In the other instance, the model deals with the combined effects of vertical migration and horizontal advection on the spatial patterns of four species of Pteropods in a cyclonic Gulf Stream ring. This form of the model contains only components dealing with horizontal current velocity fields and vertical migrations. However, one simulation involves a predator-prey submodel. The Gulf Stream ring study is a numerical experiment not backed by sampling data. It clearly demonstrates the dangers of not including spatial considerations in certain classes of marine ecosystems models.Item A study of food habits of two species of silverside, Menidia beryllina (Cope) and Membras martinica (Valenciennes), in upper Galveston Bay, Texas.(Texas A&M University., 1974) Dixon, C.A.;The food habits of the tidewater silverside, Menidia beryllina, and the rough silverside, Membras martinica, from upper Galveston Bay, were investigated. Both species of fishes were found to be omnivorous and opportunistic, feeding upon available or abundant food items. Both species changed their food habits with successive increases in size. Important foods for M. beryllina 10-49 mm consisted of Acartia tonsa, nauplii, polychaetes, and some harpacticoids. Important foods for M. beryllina, 50 mm and larger consisted of some insects, polychaetes, and smaller fish. Smaller M. martinica 10-49 mm used Acartia tonsa, nauplii, insects, algae, and invertebrate eggs, with the 50 mm and larger fish switching to a diet of mostly insects and insect larvae. Both species demonstrated late morning peaks in feeding activity, however, only M. beryllina displayed a pronounced late afternoon peak. Both species appear to avoid competing with each other through the use of different food types. Those food items that were used by both species tended to be those organisms which were present in high abundances during certain times of the year. M. beryllina appeared to feed from all areas of the water column possibly favoring the benthic and mid-water zones. M. martinica appeared to favor the mid-water and surface portions of the water column.