INFLUENCE OF ENVIRONMENTAL FACTORS ON THE PHYSIOLOGICAL CONDITION AND HEPATIC ETHOXYRESORUFIN O-DEETHYLASE (EROD) ACTIVITY OF GIZZARD SHAD (DOROSOMA CEPEDIANUM)

The tapeta lucida of three species of teleosts were examined to determine the composition of the reflecting material. The fishes were bay anchovy Anchoa mitchilli (Engraulidae), gizzard shad Dorosoma cepedianum (Clupeidae) and pigfish Orthopristes chrysopterus (Haemulidae). The tapetum of each species was situated in the pigment epithelium of the eye. That of the pigfish contained triglycerides identified as chiefly glyceryl tridocosahexaenoate. A reduced pteridine, 7, 8-dihydroxanthopterin, occurred in the tapetum of the gizzard shad. Guanine occurred in the tapetum of the bay anchovy. The tapetum of the shad contained brightly reflecting particles about 0.5 μm in diameter There were 10.8 mg of dihydroxanthopterin in the tapetum of a shad (total body length 23 cm) and 0.46 mg of guanine in the tapetum of an anchovy (total body length 9 cm). This is the first report of a pteridine acting as a retinal reflector in vertebrates. Various aspects of retinal reflectors of teleosts are discussed and their variety and common characteristics commented upon.

Download Full-text

Digestive enzyme and gut surfactant activity of detritivorous gizzard shad (Dorosoma cepedianum)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-036 ◽

2000 ◽

Vol 57 (6) ◽

pp. 1113-1119 ◽

Cited By ~ 15

Author(s):

James C Smoot ◽

Robert H Findlay

Keyword(s):

Enzyme Activity ◽

Protease Activity ◽

Feeding Strategy ◽

Digestive Enzyme ◽

Artificial Substrates ◽

Gizzard Shad ◽

Dorosoma Cepedianum ◽

Digestive Physiology ◽

Protease Enzyme ◽

Surfactant Activity

Measuring digestive enzyme and surfactant activities tested specialization of gizzard shad (Dorosoma cepedianum) digestive physiology to a detritivorous feeding strategy. Digestive enzyme activity was measured in adult and larval gizzard shad using fluorescently labeled artificial substrates. Surfactant activity in gizzard shad was measured by comparing gut juice drop diameters over a range of dilutions. Enzyme activity in the ceca region of adult gizzard shad was high for esterase, beta-glucosidase, lipase, and protease. Enzyme activity was lower in posterior intestine sections than in anterior intestine sections, although protease activity remained high for the greatest distance in the intestine. Micelles were detected in adult gizzard shad gut juice, and surfactant activity was greatest in the ceca region. Larval gizzard shad protease activity was similar to that of adult fish, and surfactants were below their critical micelle concentration. Gizzard shad coupled digestive physiology with gut anatomy to obtain nutrients from detritus, and these adaptations may explain elevated growth rates observed in these fish when they are planktivorous.

Download Full-text

The role of water ventilation and sediment ingestion in the uptake of benzo[A]pyrene in gizzard shad (dorosoma cepedianum)

Environmental Toxicology and Chemistry ◽

10.1002/etc.5620151015 ◽

1996 ◽

Vol 15 (10) ◽

pp. 1752-1759 ◽

Cited By ~ 14

Author(s):

Alan S. Kolok ◽

James N. Huckins ◽

Jimmie D. Petty ◽

James T. Oris

Keyword(s):

Gizzard Shad ◽

Dorosoma Cepedianum

Download Full-text

FAKTOR-FAKTOR YANG MEMPENGARUHI TOKSISITAS BAHAN PENCEMAR TERHADAP ORGANISME PERAIRAN

OSEANA ◽

10.14203/oseana.2017.vol.42no.2.43 ◽

2019 ◽

Vol 42 (2) ◽

pp. 12-22

Author(s):

Triyoni Purbonegoro

Keyword(s):

Environmental Factors ◽

Physicochemical Properties ◽

Aquatic Environment ◽

Aquatic Ecosystems ◽

Physiological Condition ◽

Aquatic Organisms ◽

Combined Effects ◽

Biological Factors ◽

Factors Affecting ◽

Major Factors

FACTORS THAT AFFECTING THE TOXICITY OF POLLUTANTS TO AQUATIC ORGANISMS. There are a large number of pollutants in aquatic environment with various characteristics and factors that can modify and affect the toxicity of pollutants in this environment. The major factors affecting pollutant toxicity include physicochemical properties of pollutants, mode of exposure, time, environmental factors, and biological factors. Moreover, organisms in an aquatic ecosystem are seldom exposed to only single pollutant, and most cases the stress of pollution on aquatic ecosystems is related to the interaction and combined effects of many chemicals. The combined effects may be synergistic or antagonistic, depending on the pollutants and the physiological condition of the organism involved.

Download Full-text