Electron microscopy of gut contents and faeces of Euphausia superba DANA

スポンサーリンク

概要

• 論文の詳細を見る

• Research on the diet and feeding of krill can broadly be divided into three main approaches. a) Investigations of the feeding apparatus, including anatomy and hydrodynamics. b) Grazing experiments. c) Investigation of gut contents and faecal material. Studies on the feeding apparatus indicate that E. superba is able to ingest food particles spanning a wide size range, including nanoplanktonic organisms (2-20μm in diameter). Organisms of this size are known to comparise a large proportion of the phytoplankton of the Southern Ocean throughout the year and represent an important potential food stock available for krill. The main components of the nanoplankton are diatoms and flagellates. Whilst most small diatoms can be identified by optical microscopy, flagellates are fragile and readily disrupted. They are difficult, if not impossible, to identify by optical microscopy in gut and faecal material. To better understand the diet and feeding preferences of krill we are undertaking electron microscopical analysis of the gut contents and faeces of wild krill. Further, we have been feeding various species of flagellates to krill in laboratory culture to investigate which structures survive digestion. These studies have shown that the organic external scales of the prasinophyte Pyramimonas gelidicola and the scales and thread-like material produced by the prymnesiophyte Phaeocystis pouchetii are not digested by E. superba. These have been found in gut and faecal material of wild krill. Large numbers of nanoplanktonic organisms occur in gut and faecal material from krill. The small diatom Nitzschia curta is especially abundant. Choanoflagellates and lightly silicified diatoms including Dactyliosolen antarcticus also occur. These studies support morphological evidence that krill feed extensively on nanoplanktonic organisms.

• 国立極地研究所の論文

著者

• Nash G.v.

  Antarctic Division Department Of Science

• Marchant H.J.

  Antarctic Division, Department of Science

• Marchant H.j.

  Antarctic Division Department Of Science

関連論文

• Electron microscopy of gut contents and faeces of Euphausia superba DANA
• SEM observations of the mouthparts from Euphausia superba DANA larvae (extended abstract)

スポンサーリンク