86 



TISSUE RESPIRATION IN INVERTEBRATES 



VARIATION IN RESPIRATORY RATE 

 DURING INSECT LIFE CYCLE 



Just as the respiratory metabolism of crus- 

 taceans is correlated closely with the stage of 

 the animal in the intermolt cycle, so the res- 

 piratory rate of an insect varies with the phase 

 of the insect in its life cycle (see also pp. 82-83). 

 Brooks (1957) reported the respiratory activity of 

 the cockroach (Periplaneta americana) to be low 

 in pink muscles of the leg and wing from nymphs, 

 higher in those of adults just after emergence, 

 and still higher in those of older adults. On the 

 other hand, no clear difference was detected by 



Allen and Richards (1954) in the leg muscle 

 of young (10- to 20-day) adults when compared 

 with older (95- to 185-day) adults. Lewis and 

 Slater (1954) and Slater and Lewis (1954) found 

 that the activity of the a-ketoglutaric oxidase 

 system in the flight muscle from adults of the 

 bluebottle fly (Calliphora erythrocepliala) was 

 relatively high right after adult emergence, 

 lower from the eighth to the tenth day, and high 

 again from the fifteenth to the seventeenth 

 day. 



RESPIRATORY RATE FOLLOWING INJURY 



Kubista (1956) reported that the endogenous 

 respiratory rate shown by isolated muscle of 

 a cut femur in the stone cricket (Tachycines 

 asynamorus) was 1.4 times that shown by muscle 

 of an uncut femur. 



When making respiratory measurements on 



tissues of a diapausing pupa, one must exercise 

 caution, for injury alone can increase the meta- 

 bolic rate both of the pupa (whole or subdivided) 

 and of its isolated tissues (see Schneiderman and 

 Williams, 1953; Harvey, 1956, 1961, MS a; 

 Shappirio, 1960). 



EFFECT OF ENVIRONMENT ON RESPIRATORY RATE 



With regard to the magnitude of the respira- 

 tory rate at various seasons, it appears that 

 endogenous oxygen uptake is greater in certain 

 tissues of pelecypod mollusks found in the 

 North Temperate Zone during the winter and 

 early spring than at other times during the year 

 (Hopkins, 1946; Kawai, 1957). Two investiga- 

 tions concerned with the effects of salinity on 



respiratory rate have revealed a general rise 

 with increasing dilution, as in the gill and 

 mantle of the quahog Mercenaria mercenaria 

 (Hopkins, 1949) and the gill of the green crab 

 Carcinus rnaenas (Pieh, 1936), or a fall, as in 

 the adductor muscle of M. mercenaria (Hop- 

 kins, 1949). 



EFFECT OF VARIOUS IONS ON RESPIRATORY RATE 



Increasing concentrations of the potassium 

 (K"*") ion induce a rise in endogenous respira- 

 tion in the heart of Helix aspersa, the dented 

 garden snail, and Mytilus galloprovincialis , a 

 mussel, as well as in the nerve of Sepia offici- 

 nalis, the cuttlefish (Cardot, Faure, and 



Arvanitaki, 1950). With the claw nerve of the 

 spider crab (Libinia emarginata) there is a rise 

 in endogenous respiratory rate with increasing 

 concentrations of K"*" ion up to a maximum of 

 40 mM per liter, then as a sharp drop (Shanes 

 and Hopkins, 1948). 



GRADIENTS IN RESPIRATORY RATE 



In the brandling or manure worm (Eisenia 

 foetida) the respiratory rate varies along the 

 length of the worm. If one plots respiratory rate 



against distance from the head, a U-shaped 

 curve with maxima at head and tail results. A 

 similar U-shaped curve of succinoxidase activ- 



