Meiofauna and its History...

The study of meiofauna is a late component of benthic research. despite the fact that meiobenthic animals have been known since the early days of microscopy (meiofauna and meiobenthos are largely used in this book as synonyms). While the terms macrofauna and microfauna had been long established. it was not until 1942 that "meiofauna" was used by MAREto define an assemblage of mobile or hapto-sessile benthic invertebrates (meiobenthos) distinguished from macrobenthos by their small size. Earlier. most researchers had referred to typical meiobenthic animals as microfauna. Derived from the Greek “meio” meaning smaller. members of the meiofauna are mobile. sometimes also hapto-sessile benthic animals. smaller than macrofauna. but larger than microfauna (a term now restricted mostly to Protozoa). Today. the size boundaries of meiobenthos are based on the standardized mesh width of sieves with 500 µm (1000 µm)as upper and 42 µm (63 µm) as lower limits: all fauna passing the coarse sieve but retained by the finer sieve during sieving is considered meiofauna. Gastrotricha, Gnathostomulida, Kinorhyncha, Loricifera and Tardigrada are exclusively meiobenthic groups.

* 1900-1950:

- First researches on meiofauna: regional taxonomic/ sistematic/ morphological descriptions of single groups, e.g., the interstitial opisthobranchs Microhedylidae or the nematodespopilating North American shores

- Between 1911 and 1935, more investigators became enumerated all taxa; but it was Remane, the “father of meiofauna research” who, on the basis of complete sampligs, fisrt recognized the rich populations in intertidal beaches, sbtidal sands, and muds and algal habitats as definable ecological assemblages

- In 1935, a british scientisti, Nicholls, studying the copepods of a Scottish sandy beach, introduced the term “interstitial fauna”

- During the 1930s – 1950s the Swedish marine biologist Swedmark originated studies on the systematics and ecology of the marine interstitial fauna, particularly the Gastrotricha

* 1950 – 1960:

- Period of accelerated interest in Meiofaunal systematics and Descriptive Ecology

* 1960-1970:

- During this period meiofauna studies enjoyed rapid growth due to a variety of factors: more scientists working on meiofauna, a renewed interest in the ecology of the animals, the development of meiobenthic research, better sampling and extracting techniques and better communication amongst meiobenthologists via the “Association of Meiobenthologists” and the Association’s Newsletter Psammonalia

- The first two-page issue of Psammonalia was mimeographed and mailed in November, 1966 by R. P. Higgins and D. J. Zinn

- During this period two general types of meiofaunal studies dominated: descriptive ecology and broadened taxonomic knowledge of various meiofaunal taxa from various habitats

* 1970-1980:

- Pollution effects on meiofauna were studied in the laboratory and in the field

- In the 1970s – 1980s a phylogenetic perspective experienced a broader emphasis


* From the 1980s:

- Researches improved in the all areas. Genetic and molecular studies have been used on the taxonomic and phylogenetic researches. More and more species have been discovered and described; and the deep sea has shown an extremely interesting and unknown fauna