the fat cycle could provide only enougli energy for about 

 1 month and is used up almost completely during matura- 

 tion of the gonads. 



The amount of energy, in calories, needed for res- 

 piration by the standing stock of sardines in the Cali- 

 fornia Current was shown to be 2.8 X 10^- kilocalories 

 per month during the years of maximum biomass. 1932- 

 1934. With the decline of the sardine biomass to the 

 1956 level, a major fraction of these calories became 

 available to other predators and may be reflected, as 

 others have postulated, in the resurgence of the numbers 

 and biomass of the northern anchovy, now the major 

 planktotrophic fish in the California Current. 



Doubt has recently been cast on the classical esti- 

 mates of the efficiency of digestion of marine organisms 

 which have been grossly overestimated if a large fraction 

 of material was lost by the excretion of soluble organic 

 matter, which is undetectable by the usual methods. Be- 

 cause of the importance of this measurement, a study 

 was begun this year to measure excreted dissolved organ- 

 ic material by the shrimp Crago sp., chosen because of its 

 large size and ease of maintenance in the laboratory. The 

 results, in fact, show that althougli soluble compounds 

 were measurable, they were always low, relative to fecal 



G. Mattson 



Physiology-aiialogrecorderof a carbon, hydrogen, nitro- 

 gen analysis apparatus. 



production, and would not seriously alter any digestion 

 coefficient estimates obtained by other methods. 



R. Lasker served as cruise leader on David Stan- 

 Jordan in June to study the physiology of fish eggs and 

 zooplankton organisms. The sea-water system was put in 



A. Gomes 



David Starr Jordan—shipboard o.xygen electrode is tested 

 prior to respiration experiments. 



21 



