CTENOPHORES IX NEW JERSEY COASTAL WATER-;. IOI 



states that Phurobraclria may be a serious enemy of the oyster in 

 Washington waters through the large numbers of the larva? of 

 the latter which it consumes. 



In a reeeiit work, the most extensive of its kind with which I 



am familiar, Miss Lebour ('22, '23) describes the food of numerous 



plankton organisms. She lists Pleurobrachia and Beroc with 



Sagittn among the miscellaneous feeders of the plankton. Where 



ihe-e t\\o ctenophores occur together Ber<>< may eat large 



number- 1. 1" Pleurobrachia, an observation which was also pub- 



li-hed by Mayer, however, in 1912. The chief food of was 



found I iy Miss Lebour to be small cnistacea, although she quotes 



our ob-i -i -\ .ition of a Beroc full of diatoms, probably Coscinodisciis. 



iri'/inn hin was found to subsist mainly upon Calamts, crab 



lar\ a . Sagitta, other Pleurobrachia, Syngnathas, voting plait r 



and pi. ii e eggs. I have not had opportunity to determine the 



do! Pleurobrachia. The Beroe which were found September 



i i. i '(-'4, were living chiefly upon Mneniiopsis. 



The abundance and persistence of Mneniiopsis in Ha; 

 Ha\ in 1923 gave opportunity to study the food habit- of this 

 i tenophc.re during the seasonal changes of the plankton. \ few 

 preliminary examinations demonstrated that at summer tempera- 

 ture.- the rate of digestion of food and the ejection of re-idne is so 

 rapid a- to make necessary the examination of the ctenophores 

 immediately upon removal from the water. In most instances 

 the -tomodeum was emptied of all its contents in from 20- 

 ,V> minutes after removal of the animals from their natural 

 surroundings. 



The i^reat transparency of this organism makes it possible to 

 identify with a high degree of accuracy the contents of the 

 M"iiiodeum without in any way disturbing the animal. In 

 making the examinations the station launch was anchored in the 

 de>ired -pot in the open bay and the ctenophores were dipped up 

 in a tinsel bowl as needed and examined immediately under the 

 binocular. 



1 hiring the summer the food of Mneniiopsis was found to 

 consist fhiefK of larval molluscs, copepods and their nauplii. 

 nannoplankton, and detritus, the relative amounts of these 

 beini; to >ome extent correlated with their abundance in the 

 plankton. In tlii> connection I wish to lay einpha>is upon a fact 



