Responses of the Crayfish, Procambarus simulans, to Respiratory Stress

The morphology of the gills of the freshwater African crab Potamon niloticus (Crustacea: Brachyura: Potamonidae): A scanning and transmission electron microscopic study

“…The blood of the decapods contains haemocyanin dissolved in plasma and in the large active species such as swimming crabs, the haemocyanin carries 90% of the blood's oxygen (Mangum & Weiland, 1975;Mangum, 1983). The oxygen extraction efficiency of the crab gills of about 7-30%, however, has been found to be very poor compared to that of about 60-80% of the crayfish (Redmond, 1955;Larimer, 1961;Larimer & Gold, 1961;Hughes er al., 1969;Johansen et al, 1970). This pathetic performance was attributed by these investigators both to structural and functional features of the gills like anatomical and physiological dead spaces, low gas permeability of the lamellar membranes, ventilation/perfusion inequalities and probably a restrictive respiratory surface area.…”

“…While the physiology and the mechanisms of gas exchange in the crabs have been relatively well studied (Cuenot, 1893;Zoond & Charles, 1931;Redmond, 1955;Vernberg, 1956;Agrawal & Tyagi, 1965;Hughes, Knights & Scammell, 1969;Johansen, Lenfant & Mecklenburg, 1970;Taylor, Butler & Sherlock, 1973;Greenaway & Taylor, 1976;Taylor & Butler, 1978;Aldrich & Cameron, 1979;Aldrich & McMullan, 1979;Burnett & Bridges, 1981;McMahon, 1981;Wood & Randall, 1981;Hawkins & Jones, 1982), the structure of the respiratory organs has not received comparable attention significantly to provide the pertinent data to facilitate extensive extrapolation of the functional observations (Burggren, McMahon & Costerton, 1974;Yang & McLaughlin, 1979). For example, the anatomical basis of the poor oxygen extraction of the crab gills observed by Redmond (1955), Larimer & Gold (1961), Hughes et al, (1969) and Johansen et al, (1970) is still unclear and the spatial disposition between the gill blood and the external medium has only been established in a few species (Hughes et al, 1969;Burggren et al, 1974). The notable morphological studies on the crab respiratory organs are those by Pearse (1929), Drach (1930), Harms (1932), Raben (1934), Gray (1957), Bliss (1968), Copeland (1968), Storch & Welsch (1975, Newel1 (1 976), Diaz & Rodriguez (1 977), Taylor & Greenaway (1 979), McLaughlin (1983), Greenaway & Farrelly (1 984), Farrelly & Greenaway (1 987) a...…”

A COMPARISON OFIN SITUANDIN VITRORESPONSES OF CRUSTACEAN HEARTS TO HYPOXIA

“…whose respiratory pigment has a high affinity for oxygen. Larimer and Gold (1961) report a P r , of 3.5 mm Hg for this crayfish. Cancer niai/ister, however, has a low oxygen affinity hemocyanin with a P-of 19.6 mm Hg at 10 C (Johansen, Lenfant and Mecklenburg, 1970).…”

CIRCULATORY ADAPTATIONS TO THE OXYGEN MINIMUM LAYER IN THE BATHYPELAGIC MYSIDGNATHOPHAUSIA INGENS

“…The data on heart rate in G. ingcns at different oxygen partial pressures are similar to those of crustacean species whose normoxic environment is near air saturation, showing comparable rates and lowered heart rates at lower environmental oxygen partial pressures (Larimer, 1962(Larimer, , 1964Larimer and Gold, 1961;Stiffler and Pritchard, 1972 J. The suggestion for these other species has been that the lower heart rates are not an adaptive response but a result of oxygen stress on the heart near or below the lower critical oxygen partial pressure (P c ).…”