POLiKEY

An information system for polychaete families and higher taxa
Version 2: 5 June 2003
by Christopher J. Glasby & Kristian Fauchald

POLiKEY is an interactive key and information system for polychaete families and higher taxa. It contains 104 polychaete taxa, comprising 17 higher-level taxa, 82 families and five subfamily groups. POLiKEY allows the user to obtain identifications of adult polychaetes from any part of the world as well as family descriptions and general information on taxonomy, biology and ecology.

POLiKEY

POLiKEY: polychaete identification and information retrieval system.

Help for First-time Users

Before proceeding to use POLiKEY we recommend reading the help file and information files, which can be accessed via the two upper left buttons once POLiKEY is opened.

If you have any other queries concerning the operation of POLiKEY please contact Christopher J. Glasby. Information on Intkey and other DELTA programs is available from:

• DELTA website

Intkey

Comments

What is POLiKEY and why was it developed?

POLiKEY is an interactive key and information retrieval system for polychaete families and higher taxa. It is underpinned by a DELTA database (Dallwitz 1980; Dallwitz, Paine & Zurcher 1993) containing 104 taxa and 134 characters. The system comprises an interactive identification program, based on Intkey (Dallwitz, Paine & Zurcher 1995), descriptions and illustrations of all polychaete families and higher taxa, a glossary of technical terms, and a comprehensive bibliography. It system provides for:

• identifications of adult polychaetes from any part of the world to family or higher taxa;
• diagnostic and full descriptions of families and higher taxa;
• images of selected species representing each taxon (more than 200 line drawings and colour photos of living polychaetes and museum specimens); over 300 colour-enhanced character images; and
• information on the taxonomy, biology and ecology of polychaetes.

POLiKEY was made to assist biologists to identify the families and higher taxa of polychaetes because:

• there is no existing key to higher taxa of polychaetes;
• existing keys to families are either difficult to use or do not include all the families¹;
• accurate family-level identification of polychaetes is critical for ecological and environmental studies²;
• polychaete biologists need a tool enabling rapid access to comparative systematic information on polychaetes.

Earlier attempts at interactive identification have been regional in scope. For example, the Expert System identification program Nereis included only the 37 families found in France (Jussien et al. 1994); the WWW key TaxInfo by the Natural History Museum (London) deals with the main benthic families of Thailand and EPIC-online (Easy Polychaete Identification Classification Online) is a WWW key to polychaete families found in Singapore waters developed by Lim Yun Ping, National University of Singapore. POLiKEY is the first interactive web-based key to include all polychaete families and higher taxa.

1. Traditional paper-based keys to polychaete families published in Day (1967), Fauchald (1977), George & Hartmann-Schröder (1985), Blake (1997) and Glasby & Fauchald (2000) have their limitations. Because of their complexity or lack of illustrations these keys are often difficult to use. More often than not beginners cannot identify a specimen to family because a critical part of the body is missing, or end up with the wrong answer because of an incorrect choice of character state. Interactive keys avoid these problems by allowing the user to use alternative character suites (if say one part of the body is missing), and by allowing more than one character state to be selected in the case of user uncertainty. For an extensive literature on interactive keys see: Applications and Documentation of the DELTA System
2. Families are the lowest taxonomic rank to which polychaetes are identified in many ecological and environmental studies. This is often done for cost-benefit reasons, but more importantly family-level identification is often sufficient (even preferable) in order to detect compositional and/or abundance differences in benthic infaunal assemblages as a result of environmental disturbance; this applies to macrobenthos and meiobenthos, and both soft and hard substrata (Heip et al. 1988; Warwick 1988; Ferraro & Cole 1990; Somerfield & Clarke 1995; Pagola-Carte et al. 2002).

History of development

Version 1: 30 August 2002, online September 2002.

Version 2: 5 June 2003, online 5 June 2003. Improvements in operation including ability to do identifications and interrogations in both normal and advanced modes, the default identification mode is now set to exclude higher taxa, improvements to the quick identification tool, user warnings have been added to inform the user about the use of certain options, and some corrections to the coding of higher taxa (and their HTML description files).

The Authors

Dr Christopher J. Glasby
Curator of Worms
Natural Sciences Museum & Art Gallery of the Northern Territory
GPO Box 4646
Darwin NT 0801
Australia

Email: chris.glasby@nt.gov.au
Tel: +61 8 8999 8108
Fax: +61 8 8999 8289

Dr Kristian Fauchald (deceased)
formerly National Museum of Natural History
Smithsonian Institution
Washington D.C.
USA

What are polychaetes?

Polychaetes are a group of segmented worms belonging to the phylum Annelida. Many text books treat them as a natural ‘monophyletic’ group and have assigned them the rank of Class. More recently they have been considered to be an unranked group of unrelated non-clitellate annelids. Polychaetes display a huge diversity of shapes and sizes, ranging in size from simple meiofaunal forms a few mm long to giant beach worms over 3 metres in length. Predatory forms are well-equipped with sensory appendages, jaws and paddle-like feet, whilst tube-dwelling forms have few appendages other than a filter- or deposit-feeding tentacular crown.

Polychaetes form a reasonably uniform ecological group with most species living in, or on, the seabed or in estuaries. They are one of the most commonly encountered and abundant animal groups in the benthos of coastal regions. Less commonly, polychaetes are found in open ocean waters, in river and lake sediments, moist terrestrial habitats, and some species (e.g. most notably Polynoidae) are symbiotic or parasitic on other marine animals. Polychaetes are an important group both ecologically and economically. Ecologically, they are at (or near) the base of many food chains involving commercially important fish and shellfish species, they are common commensal organisms, they play a major role in nutrient recycling, some tubiculous species are reef builders, boring species are reef destroyers, and some species are bioindicators of the health of marine ecosystems. Polychaetes are also an important economically in both positive and negative ways. Species of Nereididae, Glyceridae, Onuphidae and Eunicidae are cultured or wild-harvested for bait or for use as feed in fish and shellfish mariculture. Parasitic species may have a negative effect on the shellfish (e.g. oysters) and others have a negative effect on shipping (hull fouling) and power stations (fouling water intake pipes). from a scientific point of view, polychaetes are a key group in phylogenetic studies of the evolution of complex invertebrates and a model group in studies of invertebrate reproduction and development.

Polychaetes are an ancient group dating back to the Middle Cambrian (540 million years ago), and possibly earlier. However, because they do not fossilise well — usually only the jaws, chaetae, tubes and burrows leave imprints — there are large gaps in the fossil record. To date, about 13 000 polychaete species have been described for the world. The actual number of species is estimated to be 25 000 to 30 000 (Mackie, Parmiter & Tong 1997). So, probably there remains over half the actual number of polychaetes to describe. There are presently over 1000 genera, 82 families and 17 higher taxa, which currently have no formal Linnaean rank. Some families and many genera undoubtedly will require revision as the group becomes better known and understood.