The postembryonic developmental stages of a fresh-water calanoid copepod, epischura massachusettsensis pearse

1955 ◽  
Vol 96 (3) ◽  
pp. 441-471 ◽  
Author(s):  
Arthur G. Humes
Keyword(s):  
Fresh Water ◽  
Calanoid Copepod ◽  
Developmental Stages

Report of Acineta euchaetae Sewell, 1951 from new locality of the Arabian Sea with notes on their taxonomy and distribution

Zootaxa ◽  
2021 ◽  
Vol 5039 (2) ◽  
pp. 291-298
Author(s):  
TAPAS CHATTERJEE ◽  
IGOR DOVGAL ◽  
VERONICA FERNANDES ◽  
AMRITA BHAUMIK ◽  
MANDAR NANAJKAR
Keyword(s):  
Adult Male ◽  
Arabian Sea ◽  
Calanoid Copepod ◽  
Developmental Stages ◽  
Systematic Position ◽  
Inland Waters ◽  
Ciliate Species ◽  
Rear Part

The article deals with the data about new find of the rare suctorian species Acineta euchaetae Sewell, 1951 on calanoid copepod host Euchaeta marina (Prestandrea, 1833) from the Arabian Sea. Seven young (sub-adult) individuals of the ciliate were observed on rear part of cephalothorax and on abdomen of adult male of copepod. The data about all known finds of A. euchaetae are discussed as well as the information on different developmental stages of the ciliate species. It is suggested that A. euchaetae is euryhaline species distributed in Eurasian coastal and inland waters and have preference for calanoid copepod hosts, but do not show specificity to any calanoid genus or species. The summarized diagnosis and refined systematic position of A. euchaetae are also provided.   

Dietary Change during Development in the Freshwater Calanoid Copepod Epischura lacustris Forbes

1986 ◽  
Vol 43 (5) ◽  
pp. 938-944 ◽  
Author(s):  
Patricia Chow-Fraser ◽  
C. Kim Wong
Keyword(s):  
Developmental Stage ◽  
Calanoid Copepod ◽  
Developmental Stages ◽  
Adult Stage ◽  
Prey Selection ◽  
Ingestion Rate ◽  
Grazing Rate ◽  
Linear Dimensions ◽  
Selection For ◽  
Omnivorous Diet

The diet of the freshwater calanoid copepod Epischura lacustris from C2 to adult stage was examined with predation experiments, grazing experiments, and stomach content analyses. There was a transition from an exclusively herbivorous diet in early copepodid stages to an omnivorous diet in adults. Laboratory predation experiments revealed that C2 and C3 were incapable of ingesting Bosmina (0.25–0.35 mm), but from C4 to C6, ingestion rate of Bosmina increased with developmental stage. The order or prey selection for adult Epischura was Bosmina over Diaptomus and Cyclops. Grazing rate on small algae (<10 μm) increased with developmental stage. Zooplankton remains were only found in the guts of stages older than C2; cladocerans and crustacean eggs were the most common zooplankton food. Algae with longest linear dimensions greater than 10 μm (e.g. Sphaerocystis, Dinobryon, and diatoms) were common in the guts of all developmental stages of Epischura. The occurrence of small unicells (<10 μm) in the guts decreased with developmental stage.

Meristic variation in a clone of the cyprinodont fish Rivulus marmoratus related to temperature history of the parents and of the embryos

1986 ◽  
Vol 64 (7) ◽  
pp. 1444-1455 ◽  
Author(s):  
D. P. Swain ◽  
C. C. Lindsey
Keyword(s):  
Fresh Water ◽  
Developmental Stages ◽  
The Self ◽  
Temperature History ◽  
Vertebral Number ◽  
Rivulus Marmoratus ◽  
Temperature Regimes ◽  
Meristic Counts ◽  
History Of ◽  
Meristic Variation

Parents from one clone of the self-fertilizing cyprinodont fish Rivulus marmoratus were held at 25 or 30 °C, and their offspring were subjected to either a sustained temperature of 25 or 30 °C or to a temperature break (abrupt transfer in either direction between 25 and 30 °C) at various developmental stages. Effects of parental temperature before fertilization on meristic counts of offspring were determined both by comparing offspring produced either soon or long after parents had been transferred to a new temperature, and also by examining meristic responses of developing embryos to temperature breaks. Both line of evidence indicate that a parental temperature of 30 °C produces fewer vertebrae (0.31), pectoral rays (0.54), and caudal rays (1.11) than does one of 25 °C, in offspring reared under comparable temperature regimes. Neither line provides clear evidence of an effect of parental temperature on number of anal or dorsal rays in offspring. Responses of all five meristic series to temperature breaks in either direction were extralimitary (beyond the counts produced by sustained incubation at either temperature) and were satisfactorily fitted by an "atroposic" model described previously. Embryos transferred to fresh water during development tended to have higher meristic counts than those with sustained rearing in brackish water, but counts among embryos transferred to fresh water at different developmental stages differed significantly only for caudal rays. Only dorsal ray numbers differed significantly among embryos retained within parents for different times after fertilization. Previous studies claiming uniquely high thermolability of vertebral number in R. marmoratus are re-evaluated; thermolability of vertebral number in R. marmoratus is concluded to be within the range reported for other species.

NEW RECORDS AND SPECIES OF CALANOID COPEPODS FROM SASKATCHEWAN AND LOUISIANA

1958 ◽  
Vol 36 (4) ◽  
pp. 489-497 ◽  
Author(s):  
Mildred Stratton Wilson
Keyword(s):  
New Species ◽  
Fresh Water ◽  
Calanoid Copepod ◽  
New Records ◽  
Water Bodies ◽  
Calanoid Copepods ◽  
Check List ◽  
Three New Species

Diagnoses are given for three new species of the fresh-water calanoid copepod genus Diaptomus (subgenera Hesperodiaptomus and Aglaodiaptomus) from Saskatchewan and Louisiana. A check list of the calanoid copepods of Saskatchewan includes 23 species, of which 8 were previously reported in the literature, and 15 are new additions resulting from examination of collections from various types of water bodies.

Trypanosomes and dactylosomes from the blood of fresh-water fish in East Africa

Parasitology ◽  
1960 ◽  
Vol 50 (3-4) ◽  
pp. 515-526 ◽  
Author(s):  
J. R. Baker
Keyword(s):  
East Africa ◽  
Fresh Water ◽  
Developmental Stages ◽  
Infected Fish ◽  
Conclusive Evidence ◽  
Fresh Water Fish ◽  
Water Fish

1. Trypanosomes were found in the blood of thirty-five of seventy-two fish of five genera (chiefly Tilapia spp.) from Lakes Victoria and George, Uganda.2. The trypanosomes, which were never numerous in the blood, showed two morphological forms—small (22–44μ. long) and large (45–65μ). No significant differences were observed between the trypanosomes from the different species of fish, and all the trypanosomes seen are provisionally identified as Trypanosoma mukasai Hoare, 1932.3. Crithidia were found in the gut of a glossosiphoniid leech which had been removed from a fish; although suggestive, this cannot be taken as conclusive evidence that leeches of this family are vectors of T. mukasai.4. The taxonomy of the trypanosomes of African fresh-water fish is reviewed, and it is concluded that only the following species should be regarded as valid at present: T. toddi Bouet, 1909, T. mukasai Hoare, 1932, and T. tobeyi Dias, 1952.5. Dactylosoma mariae Hoare, 1930, was found in the blood of thirty-six of the seventy-two fish examined. Merozoites, schizonts and gametocytes of this small unpigmented parasite were observed within erythrocytes. No developmental stages were found in certain viscera of two infected fish.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

Electron investigations of rhabdovirus-like particles in mexican bean beetles and crickets

1978 ◽  
Vol 36 (2) ◽  
pp. 378-379
Author(s):  
J. R. Adams ◽  
G. J Tompkins ◽  
A. M. Heimpel ◽  
E. Dougherty
Keyword(s):  
Biological Control ◽  
Integrated Pest Management ◽  
Pest Management ◽  
Developmental Stages ◽  
Management Program ◽  
Acheta Domesticus ◽  
Epilachna Varivestis ◽  
House Cricket ◽  
Similar Morphology ◽  
Bean Beetle

As part of a continual search for potential pathogens of insects for use in biological control or on an integrated pest management program, two bacilliform virus-like particles (VLP) of similar morphology have been found in the Mexican bean beetle Epilachna varivestis Mulsant and the house cricket, Acheta domesticus (L. ).Tissues of diseased larvae and adults of E. varivestis and all developmental stages of A. domesticus were fixed according to procedures previously described. While the bean beetles displayed no external symptoms, the diseased crickets displayed a twitching and shaking of the metathoracic legs and a lowered rate of activity.Examinations of larvae and adult Mexican bean beetles collected in the field in 1976 and 1977 in Maryland and field collected specimens brought into the lab in the fall and reared through several generations revealed that specimens from each collection contained vesicles in the cytoplasm of the midgut filled with hundreds of these VLP's which were enveloped and measured approximately 16-25 nm x 55-110 nm, the shorter VLP's generally having the greater width (Fig. 1).

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