New Phreodrilidae (Annelida: Clitellata) from Tasmanian estuaries

Abstract

A new species of Phreodrilidae from Macquarie Harbour, Tasmania is described. Astacopsidrilus ostiensis sp. nov. is unique in possessing the combination of long, tightly folded atria, modified spermarhecal chaetae and ventral chaetae that are almost simple pointed. These are the first phreodrilids to be recorded from estuarine or intertidal habitats, other than two species collected from beaches, on Subantarctic Campbell Island, for which the habitat data are ambiguous. The existence of other Phreodrilidae from Tasmanian estuaries, of which we do not have sufficient material for description, is noted. Key Words: Clitellata, Phreodrilidae, estuaries, Tasmania, new species. INTRODUCTIONIn recent decades, hundreds of new oligochaetes in the families T ubificidae and Enchytraeidae have been described from marine and estuarine environments in Australia and elsewhere (e.g. Jamieson 1977, Erseus 1981, 1990a,b, 1993, 1997a,b, Erseus & Jamieson 1981, Coates 1990, Healy & Coates 1997, exceeding the number of species of these families from inland waters. By contrast, of the 45 described species of Phreodrilidae and others awaiting description in the first author's collection, almost all appear to be restricted to inland freshwater habitats such as streams and lakes (Martin & Brinkhurst 1994, Giani et al. 1995, Martin & Giani 1995, Pinder & Brinkhurst 1997.Of the phreodrilids, the only record of Insulodrilus litoralis (Michaelsen 1924) is of the type specimens which were collected at Perserverence Harbour, Subantarctic Campbell Island, from under a rock on the beach at ebb-tide. While this may be a marine littoral species there is no information about salinity at the type locality. Astacopsidrilus campbellianus (Benham 1909) was also collected on a Campbell Island beach, but near the outlet of a freshwater stream and the species is common in freshwater streams of Macquarie Island, 900 km west of Campbell Island (Marchant & Lillywhite 1994). Finally, the type locality of Antarctodrilus niger (Beddard 1894) is given as Port Stanley, Falkland Island, by its original author, but Michaelsen (1900) expanded on this, giving the locality as "zwischen Algen in einem langsam fliessenden Bach" (among algae in a slow flowing brook). All other phreodrilids identified as A. niger (or its synonyms) are from inland streams and rivers (Beddard 1894, Goddard & Malan 1913, Brinkhurst 1966, 1982.The new species and other, unnamed, material described in this paper were collected from brackish reaches of estuaries in Tasmania. These were part of a collection of oligochaetes obtained during an extensive biological study of Tasmanian estuaries (Edgar et al. 1998), which was placed at the second author's disposal. MATERiALS AND METHODSThe material used in this study was collected by Neville Barrett (Tasmanian Aquaculture and Fisheries Institute) and kindly forwarded to us by Graham Edgar (University of Tasmania). The specimens were fixed in formalin, and subsequently transferred to 80% ethyl alcohol. Some worms were stained in alcoholic paracarmine...

Phylogeny of oligochaetous Clitellata

“…1: Phr) is a tetragonadal aquatic taxon with about 50 described species, largely confined to the Southern Hemisphere (Pinder & Brinkhurst, 1997a), and with a few also known from Sri Lanka and Northern Africa (Giani et al, 1995). Most phreodrilids live in freshwater sediments, some are commensal on freshwater crayfish, and there are a few records from estuarine or intertidal habitats (Pinder & Erse´us, 2000). They are of about the same size as tubificids and often bear bifid and capillary chaetae, but they also have chaetal types (e.g., 'support chaetae'; see Pinder & Brinkhurst, 1997a) found nowhere else within Clitellata.…”

Description of ovary organization and oogenesis in a phreodrilid clitellate

“…Phreodrilidae is a small (about 50 currently described species—Pinder, ) annelid family comprising minute clitellates (collectively known as microdriles) inhabiting mainly freshwaters in the Southern hemisphere. Generally, phreodrilids live in freshwater sediments, however there are also reports that some inhabit estuaries and intertidal zones (Pinder & Erséus, ; Erséus, ) and even forest litter (Stout, ). Their distribution suggests a Gondwanan origin (Pinder & Brinkhurst, ; Pinder, ; Martin, Martínez‐Ansemil, Pinder, Timm, & Wetzel, ) and only a few species have been found in the Northern hemisphere (Giani, Martin, & Juget, , Martin & Ohtaka, , Martínez‐Ansemil, Sambugar, & Giani, ; Stephenson, ).…”

Hyporheic annelid distribution along a flow permanence gradient in an alluvial river

“…The relative abundance of eyeless Nais communis was higher in the perennial-gaining reach than in the other reaches (p \ 0.05, Scheffé tests). Types of Phreodrilidae; BM ventral bundles with one simple-pointed and one bifid crotchets; 2M ventral bundles with two simple-pointed crotchets; 2B ventral bundles with two bifid crotchets; the used nomenclature conformed to the last ICZN rules (Erséus et al 2008); (1) Brinkhurst and Jamieson (1971) (2001); (5) Kasprzak (1973); (6) Juget and Dumnicka (1986); (7) Nielsen and Christensen (1959); (8) Brinkhurst (1990);Pinder (2008); Pinder and Brinkhurst (1997); Pinder and Erséus (2000) EPI epigean, HYPO hypogean, DR desiccation resistance, U undetermined, NR non resistant, R resistant, TI total individuals, RA: relative abundance, FO frequency of occurrence…”