Daily rhythms of swimming activity, synchronization to different feeding times and effects on anesthesia practice in an Amazon fish species (Colossoma macropomum)

Myxosporea parasitize many organs in fresh and saltwater fish. Species of the genus Myxobolus parasitizing the gills and other organs of the tambaqui Colossoma macropomum have been described. In the present study, blood smears were made from juvenile tambaqui and were stained with May Grunwald-Giemsa-Wright in order to identify myxozoan parasites. Out of a total of 36 fish examined, one specimen (2.7%) that was reared in a cage presented spores that were identified as M. colossomatis, whereas fish kept in 250 L tanks showed prevalence of 5.5%. This is the first report of M. colossomatis in the blood of farmed tambaqui in the Amazon region. These results indicate that myxozoan parasites should also be investigated in fish blood smears. Some myxosporean species may cause diseases in fish, and these species need to be identified so that adequate preventive sanitary control can be instituted.

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Effects of hydrogen sulfide (H2S) in the Amazon fish, Colossoma macropomum (Characiformes, Serrasalmidae)

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology ◽

10.1016/s1095-6433(99)90427-0 ◽

1999 ◽

Vol 124 ◽

pp. S108

Author(s):

EG Affonso ◽

VLP Polez ◽

CF Corrêa ◽

AF Mazon ◽

MRR Araújo ◽

...

Keyword(s):

Hydrogen Sulfide ◽

Colossoma Macropomum ◽

Amazon Fish

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Acute and Final Temperature Preferenda as Predictors of Lake St. Clair Fish Catchability

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f91-168 ◽

1991 ◽

Vol 48 (8) ◽

pp. 1408-1418 ◽

Cited By ~ 7

Author(s):

Roy G. Danzmann ◽

Don S. MacLennan ◽

Don G. Hector ◽

Paul D. N. Hebert ◽

Jurek Kolasa

Keyword(s):

Regression Analysis ◽

Water Temperature ◽

Fish Species ◽

Swimming Activity ◽

Final Temperature ◽

Preferred Temperature ◽

Different Temperatures ◽

Temperature Preferences ◽

Geographic Distributions

Geographic distributions of major fish species resident in Lake St. Clair, field assessments of their seasonal thermal distributions, and laboratory determinations of their median and maximum final temperature preferenda were compared with their catchability at different temperatures. Fish catchability at various temperatures was estimated (regression analysis) during the fall pound net set survey (1977–88) using number of fish caught per 24-h net set as the dependent variable. Swimming activity was expected to be higher at temperatures closest to the species' preferred temperature, thereby increasing catchability. Maximum final temperature preferendum was the best predictor of observed fish temperature preferences. Geographic distributions and median final temperature preferenda were better predictors than summer or fall seasonal thermal distributions. Acute temperature preferenda were also good predictors of fish catchability at different temperatures. Of the 22 species examined, the catchability of Centrarchidae (five of six species), Catostomidae (two of five species), Clupeidae (one species), Ictaluridae (two species), and Percichthyidae (two species) was greater in warmer water, while the catchability of Amiidae (one species), Cyprinidae (one species), Catostomidae (three of five species), Esocidae (one species), Percidae (two species), and Sciaenidae (one species) increased in colder water. Temperature significantly accounted for differences in catchability among most species (14 of 22).

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