Howard M. Lenhoff

Hydra : research methods

Main entry under title: Hydra: research methods. Includes bibliographical references and index. No part of this book may be reproduced, stored in a retrieval System, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher

Culturing Large Numbers of Hydra

To grow in the laboratory mass cultures of hydra by two methods: the tray method, which yields numbers of animals ranging from 10,000 to 100,000 at a time; and the vertical plate method, which can yield kilogram quantities (wet weight) monthly.

Water, Culture Solutions, and Buffers

To provide directions for preparing a variety of solutions in which hydra can he cultured or maintained for extended periods.

A View of the Evolution of Chemoreceptors Based on Research with Cnidarians

Since Loomis (1955) discovered that reduced glutathione (GSH) was the specific activator of feeding in Hydra littoralis, research on cnidarian chemoreceptors has taken two lines. One, involving mostly work on hydra, is concerned with elucidating the mechanism by which the receptor is activated (see Lenhoff, 1974). The other is of a more comparative nature showing that numerous compounds activate feeding in a wide range of cnidarians.

Regulation of Feequency of Pedal Laceration in a Sea Anemone

Many acontiate sea anemones (Subtribe Acontiaria) undergo pedal laceration as a primary method of asexual reproduction (Stephenson, 1920 and 1929). Pedal laceration consists of a radial spreading of the pedal disc followed by the separation of a more or less complete ring of tissue derived from the peripheral margin of the disc. This ring subsequently fragments into two to eight pieces of tissue, each of which develops in about two weeks into a small anemone capable of feeding.

Bioassay for, and Characterization of, Activators and Inhibitors of the Feeding Response

To describe conditions of the bioassay and the means for quantifying the potency of activators and inhibitors of the feeding response.

Hatching Brine Shrimp Larvae Axenically and/or in a Range of Quantities

To hatch a range of quantities of brine shrimp for feeding hydra, and to prepare axenic larvae (i.e. free of other organisms).

Turbidimetric and Pipetimetric Measurements of Number of Hydra

To determine rapidly and accurately the number of hydra in dense suspensions by the turbidity of diluted hydra homogenates or by the volume they occupy in a pipet.

Spectrophotometric Assay for Maltose

To quantify spectrophotometrically maltose secreted by isolated endosymbiotic algae in vitro.

Rapid Whole-Mount Radioautography

To prepare labeled live hydra as intact extended specimens for whole-mount radioautographs.