The purpose of this webpage is to present the physical characteristics of a group of organisms belonging to the phylum Nematoda. This phylum encompasses an order of about 12,000 different species. Their distribution is worldwide ranging from terrestrial to aquatic species with very few species specific to wastewater treatment and a few introduced into the wastewater environment through rainfall events. The distinguishing characteristics of this phylum are their cylindrical shape: their flexible nonliving cuticle (skin); their lack of motile cilia or flagella (such as those present in annelids which are sometimes used for locomotion); and the muscles on their body walls run in a longitudinal direction only. Free living nematodes feed on bacteria, yeasts, fungal hyphae, and alga. Predatory nematodes may eat rotifers, tardigrades (water bears) small annelids, and other nematodes. Some species can endure temperatures extremes and desiccation by passing into a state of suspended animation (cryptobiosis) and reviving when conditions are more favorable. The phylum Nematoda includes the following Classes Phasmidia (Ascaris limbricoides—common ground worm, Rhabditoidae Superfamily, and Superfamily Diplogasteroideae and Class Aphasmidia (Trichinella and Plectus).
Nematodes prefer a quiescent environment as well as long detention times that will allow them to go through their entire life cycle. Some nematodes have two distinctive sexes and both are required for replication, other nematodes are hermaphroditic or parthenogenetic. Trickling filters as well as biological membranes are the preferred environment of nematodes. By perforating through biological layers (ingesting the outer portions as well as boring through), nematodes allow the diffusion of oxygen as well as nutrients to the inner layers of both flocs and biological membranes. Aeration basins are not conducive to nematode growth and replication. The majority of nematodes found in aeration basins are attributed to them being washed from trickling filters, industry
discharges into the sewer system, and any thick biological growth found on the aeration basin walls, where annelids and nematodes can bore through and maintain a quiescent living within the growth.
Rhabditis is featured in the video below.
to laying eggs.