Food of Juvenile American Shad, Alosa sapidissima, Juvenile Blueback Herring, Alosa aestivalis, and Pumpkinseed, Lepomis gibbosus, in the Connecticut River below Holyoke Dam, Massachusetts

Estuaries ◽  
1980 ◽  
Vol 3 (1) ◽  
pp. 65 ◽  
Author(s):  
Robert B. Domermuth ◽  
Roger J. Reed
1987 ◽  
Vol 65 (6) ◽  
pp. 1559-1563 ◽  
Author(s):  
L. A. Rubec ◽  
W. E. Hogans

The male and female of Clavellisa cordata Wilson, 1915 are described from the gills of blueback herring (Alosa aestivalis), alewife (Alosa pseudoharengus), and American shad (Alosa sapidissima) collected in New Brunswick. The female differs from the original description in the presence of uropods, the apical armature of the first antennae, second antennae, and first maxillae, the presence of secondary teeth on the mandibles, and several additional processes on the maxillipeds. The male differs in the presence of uropods and in the detailed morphology of the various appendages, in particular the maxillipeds. Distinctive features of Clavellisa spinosa, another species occurring in the northwestern Atlantic, are briefly discussed. Differences between Clavellisa cordata and a closely related species, Clavellisa emarginata, occurring in the northeastern Atlantic, are listed. The present redescription of Clavellisa cordata represents a northern range extension and three new Canadian host records.


Author(s):  
Foivos A. Mouchlianitis ◽  
Eric T. Schultz ◽  
Thassya C. Santos Schmidt ◽  
Justin P. Davis ◽  
Kostas Ganias

1972 ◽  
Vol 29 (10) ◽  
pp. 1495-1499 ◽  
Author(s):  
Raymond C. Levesque ◽  
Roger J. Reed

Food habits of young American shad (Alosa sapidissima) were studied in the Connecticut River above Holyoke, Massachusetts, 1969. Diurnal feeding data revealed a peak in stomach content volume at 8:00 PM during midsummer. Larval shad fed mainly on aquatic crustaceans and tendipedid larvae and pupae. Juveniles ingested the most abundant organisms: crustaceans, tendipedid larvae and pupae, hydropsychid larvae and adult insects. Electivity data indicated positive selection for tendipedid pupae and crustaceans and negative selection for hydropsychid larvae and tendipedid larvae. Selection of Trichoptera larvae by young shad in significant amounts was documented for the initial time.


1973 ◽  
Vol 30 (12) ◽  
pp. 1847-1860 ◽  
Author(s):  
Julian J. Dodson ◽  
William C. Leggett

The migratory behavior of American shad (Alosa sapidissima) approaching their natal river during the final saltwater stage of the spawning migration was studied using ultrasonic tracking and conventional tagging procedures. Initial displacement of most sonic-tagged shad released without displacement adjacent to and 10 km west of the Connecticut River was not in the direction of the home river. These fish, however, homed successfully to the Connecticut River as did dart-tagged shad released in the same areas.Shad exhibited two major behavior patterns; countercurrent orientation in response to the reversing tidal current and adjustment of swimming speed to changes in tidal velocity. Countercurrent orientation was equally significant during daylight and darkness, whereas the adjustment of swimming speeds to tidal current velocity was more significant during daylight than darkness.Shad tracked to the west exhibited a westerly bias inherent in the basic open water behavior patterns. Shad exhibited a greater degree of directed movement when oriented against the ebb tide and adjusted their swimming speeds to exceed the ebb tide velocity and to approximately equal the flood tide velocity. Shad tracked to the east exhibited the same major behavior patterns but with the opposite directional bias.A hypothesis is presented suggesting that the location of the home river is achieved by means of a nonrandom search. Environmental clues indicative of the Connecticut River act to establish a preferred direction of displacement while the actual unidirectional displacement is achieved by reference to the rate and direction of tidal currents.


1990 ◽  
Vol 47 (8) ◽  
pp. 1570-1577 ◽  
Author(s):  
Michael H. Prager ◽  
Mary C. Fabrizio

We examined the applicability of logistic regression to stock identification studies and compared its performance on two data sets to that of linear and quadratic discriminant functions. Logistic regression can be used to model a categorical dependent variable associated with continuous or discrete independent variables, and is preferred to discriminant analyses when the explanatory variables are not multivariate normal. Our examples were American shad (Alosa sapidissima) from the Connecticut River and Hudson River estuaries, and striped bass (Morone Saxatilis) from the Hudson River, Chesapeake Bay, and Roanoke River estuaries. In the examples we used a resampling method to assess classification and allocation errors of the two methods on new data. For the shad data, the logistic model classified significantly more fish correctly, and provided a significantly better estimate of stock composition. For the striped bass data, the two methods classified about the same proportion of fish correctly, but the logistic model gave a significantly better estimate of stock composition.


1998 ◽  
Vol 55 (2) ◽  
pp. 431-437 ◽  
Author(s):  
Karin E Limburg

Anadromous herrings of the genus Alosa are generally thought to leave their natal river or estuary at the end of the first growing season and return as mature adults to spawn. Nevertheless, immature yearling alosines have been observed in large numbers in the Hudson River estuary during and after the spring spawning run. I analyzed the stable isotopic ( delta 13C, delta 15N) compositions of 26 blueback herring (Alosa aestivalis), eight American shad (Alosa sapidissima), and 10 alewife (Alosa pseudoharengus) collected from 55-225 km above the estuary mouth during April-July and compared them with isotopic compositions of young-of-year (resident) alosines, as well as adults (marine phase). delta 13C of the May-caught American shad and alewife indicated a marine origin (greater than -22.5omicron); blueback herring split into both marine and freshwater ( delta 13C less than -25.5omicron) groups. June-caught fish had intermediate values. Microprobe traces of Sr in these fishes' otoliths helped further to discriminate between resident fishes and those that had migrated to sea (or brackish water) and then moved back upriver for a period of several weeks. The combination of biogeochemical tracer methods holds promise for elucidating complex life histories of fishes and helps to pose questions about plasticity of migration.


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