Subfamily Tubificinae Vejdovsky, 1876

Museums

Museum list

Regional Maps

Subfamily Tubificinae Vejdovsky, 1876

Compiler and date details

Adrian M. Pinder

Tubificidae Vejdovsky, 1876.
Type genus:
Tubifex Lamarck, 1816.

Brinkhurst, R.O. 1971. Family Tubificidae. pp. 444-625 in Brinkhurst, R.O. & Jamieson, B.G.M. (eds). Aquatic Oligochaeta of the World. Edinburgh : Oliver & Boyd 860 pp. [444]
Baker, H.R. & Brinkhurst, R.O. 1982. A revision of the genus Monopylephorus and redefinition of the subfamilies Rhyacodrilinae and Branchiurinae (Tubificidae: Oligochaeta). Canadian Journal of Zoology 59: 939-965
Erséus, C. 1990. Cladistic analysis of the subfamilies within the Tubificidae. Zoologica Scripta 19: 57-63

Introduction

The type species of this family, Tubifex tubifex Lamark (1816) was one of the first aquatic oligochaetes described and is well known to aquaculturalists as a live fish food. It is cosmopolitan in distribution, as are several of the most widespread species in Australia, such as Limnodrilus spp. and Branchiura sowerbyi. Most species, however, are endemic and represent four of the five tubificid subfamilies (Phallodrilinae, Tubificinae, Rhyacodrilinae and Limnodriloidinae). The fifth subfamily, Telmatodrilinae, was thought to be present in Australia but Pinder & Brinkhurst (2000) removed Australian species into new rhyacodriline genera, leaving it a northern Holarctic group. Phallodrilines and limnodriloidines are almost entirely marine, though some occur in fresh surface and groundwater in Europe and some undescribed phallodrilines have recently been found in Western Australian caves and groundwater. Rhyacodrilines include both marine and freshwater genera while tubificines are mostly freshwater species. Most work on Australian tubificids has been published since the 1970s, although the first endemic species were described decades earlier. Benham (1907) described Branchiura pleurotheca and Tubifex davidis from a lake in the Kosciuszko region, though the former was later synonymised with the globally widespread Rhyacodrilus coccineus, and a new genus, Antipodrilus, was erected for davidis and some new species by Brinkhurst (1971e). Michaelsen (1907) described the marine Clitellio abjornsoni from south-western Australia, which species was later moved to Coralliodrilus by Erséus (1990e). The freshwater fauna is relatively small compared to the marine fauna, with only 29 described freshwater species compared to 128 from marine habitats.

Marine tubificids are common members of interstitial communities from tidal areas to the deep sea, inhabiting sediments ranging from coarse coral sands to mud (Erséus 1988b). Like freshwater tubificids, marine species are largely detritivores, obtaining nutrition from digestion of microflora attached to ingested particles. However, two Phallodriline genera (Olavius and Inanidrilus) lack a gut, the worms instead obtaining sustenance from metabolic products excreted by symbiotic chemautotrophic bacteria living in their body walls (see for example, Erséus 1984a; Giere & Langbold 1987). These genera are mostly found in northern waters in Australia. Limnic tubificids are generally detritivores, obtaining nutrition from microflora attached to ingested sediment particles and organic matter (Brinkhurst 1974). Some undescribed phallodrilines have been found recently in fresh groundwater aquifers in coastal limestone, indicating movement of marine interstitial species into terrestrial groundwater (unpublished data). Most information about Australian marine tubificids has come from publications by Erséus (1990e, 1993b, 1997a,b), arising from a number of Marine Biological Workshops.

Freshwater tubificids are often called sludge worms for the propensity of some widespread species, such as Limnodrilus hoffmeisteri, to occur in organically polluted waters, even sewage sludge. This has sometimes led to all tubificids being labelled as 'pollution tolerant' whereas in fact many species are sensitive to organic enrichment and tubificids show a wide range of sensitivities to other pollutants such as pesticides and heavy metals (Chapman & Brinkhurst 1980; Chapman et al. 1982). Tubificids occupy a wide range of aquatic habitats, from deep lakes to small streams and ponds and have recently been found in AUstralian groundwater (unpublished data). The ecology of tubificids has been better studied than most other interstitial oligochaete families (such as the phreodrilids) and the role of these worms in processes such as sediment-water nutrient exchange (Fukuhara & Sakamoto 1987; Pelegri & Blackburn 1995), pollutant dynamics (Soster et al. 1992; Reible et al. 1996), other chemical processes (Davies 1974) and sediment structure (Fisher et al. 1980; Matisoff et al. 1999) is well known. The cosmopolitan opportunistic species Tubifex tubifex is the subject of intensive research in the Northern Hemisphere because of its role as the intermediate host of the myxozoan parasite (Myxobolus cerebralis Hofer) that causes whirling disease in salmonid fish (Wolf & Markiw 1986; Antonio et al. 1999). The presence of this species in Australia is thus of interest to the fishing industry, although the parasite itself has not yet been recorded here.

Diagnosis

Aquatic marine or freshwater oligochaetes. Ventral chaetae from II, sigmoid nodulate crotchets, usually with bifid or simple tips, usually several per bundle. Ventral chaetae of the genital region often modified. Dorsal chaetae usually from II, with thin hairs and/or sigmoid nodulate crotchet chaetae, the latter with bifid, pectinate (with intermediate teeth) or simple tips. Proboscis absent. Pharynx with thickened eversible roof in II and III and pharyngeal glands in some anterior segments. Reproduction usually sexual. Thin clitellum normally restricted to X and XI. Testes and ovaries paired in X and XI, respectively. Gonoducts paired. Male genitalia generally consisting of male funnel feeding a vas deferens, which enters an atrium (with diffuse or discrete prostate tissue attached) connected to male pores on XI, usually via an ejaculatory duct and various types of penial structures. Spermathecae normally in X, with pores on same segment. Sperm stored sometimes as discrete bundles (spermatozeugmata). Female funnels on posterior septa of testes segment lead to pores within intersegmental furrow.