Sampling, Preservation and Counting of Samples II: Zooplankton

This chapter reviews traditional and new zooplankton sampling techniques, sample preservation, and sample analysis, and provides the sources where in-depth discussion of these topics is addressed. The net systems that have been developed over the past 100+ years, many of which are still in use today, can be categorized into eight groups: non-opening/closing nets, simple opening/closing nets, high-speed samplers, neuston samplers, planktobenthos plankton nets, closing cod-end samplers, multiple net systems, and moored plankton collection systems. Methods of sample preservation include preservation for sample enumeration and taxonomic morphological analysis, and preservation of samples for genetic analysis. Methods of analysis of zooplankton samples include determination of biomass, taxonomic composition, and size by traditional methods; and genetic analysis of zooplankton samples.

On a Collection of Decapod Larvae From the Gulf of Aqaba Off the Jordanian Coast, I. Thalassinidea and Anomura

Descriptions of some decapod crustacean larvae of a plankton collection from the Gulf of Aqaba deal with Thalassinidea (Laomediidae, Upogebiidae, and Callianassidae) and Anomura (Galatheidae and Diogenidae). Discussion on generic larval characters is made particularly in Callianassidae and Diogenidae. Comparison of Laomediidae and Galatheidae larvae is summarized in tables I and II. The different arrangement of spines on some abdominal somites in Upogebiidae larvae is not a generic character but can be used, viz., in the form of distinctive larval species features. Because of confusion among the adult callianassid genera and the lack of knowledge in larval development, a definite generic identification is not possible. A key to the identification of Coenobitoidea larvae is provided. Larvae of the Coenobitidae and Calcinus are distinguished.

Methods of Plankton Collection and a Description of a New Sampler

A discussion of the composition and distribution of plankton organisms forms a basis for the presentation of a critical review of methods of plankton collection. The quantitative sampling of plankton by pumps, water samplers, tow nets, plankton traps and the Clarke-Bumpus sampler is discussed. Data of a comparative nature dealing with some of the more usual methods are presented. A new instrument, the Toronto Sampler, developed at the Ontario Fisheries Research Laboratory, is described and its performance is assessed.