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Polychaetes & Allies: The Southern Synthesis.

Polychaetes & Allies: The Southern Synthesis. Fauna of Australia. Vol. 4A Polychaeta, Myzostomida, Pogonophora, Echiura, Sipuncula. Edited by Pamela L. Beesley, Graham J. B. Ross, & Christopher J. Glasby. Published in 2000 by CSIRO Publishing, P. O. Box 1139, Collingwood, Vic 3066, Australia, (http://www.publish.csiro.au/). 477 p., hardback. ISBN 0- 643-06571-7. Price A$185. (email: sales@publish.csiro.aus)

Review 1. Dr Geoffrey B. Read, National Institute of Water & Atmospheric Research, NZ. Review reproduced with permission from: New Zealand Journal of Marine and Freshwater Research, vol.34(3):569-571, September 2000, [ NZJMFwR abstracts, year 2000 ].

The Fauna of Australia series will be of epic proportions if ever publication is completed. Intended as "authoritative syntheses of the primary zoological literature" for non-specialists, these valuable volumes have as their trademark a concentration on family- level biology. One can largely ignore the "of Australia" in the title and use the works as wide-ranging overviews in the tradition of Libbie Hyman's "The Invertebrates" and the "Traité de Zoologie" of Pierre-Paul Grassé. Additionally, in delving further down to family-level, they have rather more detail, and more original content in text and illustrations than those honoured forebears. The "Faunas" are produced by Australian Biological Resources Study, a Department of Environment and Heritage editorial group also responsible for the related "Australian Faunal Directory" species lists. They have been able to follow up the critically-praised molluscan synthesis of 1998, a massive 2- volume production, with a slimmer work on the major marine annelid group, the polychaetes.

Polychaetes are here combined with three undoubted close allies - myzostomes, pogonophores, echiurans, and one more distant group of worms, the sipunculans. The sections on the latter two are the legacy of Stanley Edmonds who died in 1995. Polychaeta, Myzostomida (Mark Grygier) and Pogonophora (Eve Southward) are treated as annelid classes, with Echiura and Sipuncula as phyla. The polychaetes occupy a massive first chapter of 296 pages, with a mere c. 20-30 pages each for the minor groups, followed by an overall glossary and an index. Each chapter has a lengthy general overview of biology and systematics, followed by comprehensive treatments for each family more specific to the Australian context, and concluding with its own literature cited (an overall total of 2370 papers). The remaining annelids, the clitellate oligochaetes and leeches, are planned for another part of volume 4 according to the schema in volume 1A, but this is not mentioned in the preface of the current volume.

Like its predecessors, "Polychaetes & allies" is technically very impressive, with high production values. An A4 format allows for uncramped figures and a double-column text in smallish print, thus a lot of information is packed within its pages. Surprisingly there are only ten authors involved, all but one are Australian residents or past workers in Australia. There is a New Zealand connection in that the third editor and major contributor to the polychaete chapter, Chris Glasby, spent several years in Wellington before returning to his homeland recently. Consequently a couple of the more obscure families that the Australians have yet to find are illustrated by original drawings of New Zealand specimens.

The colour photographs (a 12-p. set) are almost all very good indeed, only marred by one odd choice of a spionid broken at both ends. The habitus myzostome photos are particularly fascinating, probably for many bringing to life for the first time these bizarre commensals and parasites of echinoderms. Colour reproduction is limited to the central set, and thus the selection of Schmarda's rare 1861 colour plates used in the history of discovery section are only in black & white (readers may see all the plates and the missing colours via the internet at http://biodiversity.uno.edu/~worms/docs/schmarda.html). There are some other monochrome photographs, often scanning electron microscope views. The numerous whole-body original ink drawings do give a significant freshness to the book, albeit with a minor drawback that they often have been done by artists rather than the scientists, so don't always distinctly show all structures. One example is the tail-less "entire animal" of again the unfortunate spionids, a family in which pygidial ornamentations may be vital for recognising genera; presumably the illustrator did not know there was anything missing. As in earlier volumes the editors have chosen to label features with cryptic letter codes instead of fuller text, but I found many of these irritatingly unguessable and non-intuitive.

Bilaterian phylogeny and the position of the annelids and other worms are very much a hotbed of competing views. Indeed, one of the contributors to the polychaete phylogeny and classification section, Greg Rouse, has been an advocate of linking the segmented annelids and arthropods as the Articulata, a conclusion looking very doubtful currently as molecular sequence data suggests that phyla that moult (annelids donít) appear to be a separate group. This alternate hypothesis and others get a fair hearing. It is an interesting feature of this book that authors are largely non- judgmental in presenting competing ideas. Sometimes I wished they were more openly opinionated! The phylogeny presentations in the other "allies" chapters are perhaps overly brief, with the Sipuncula chapter seemingly not up to date on the issue.

The convoluted history of polychaete classification is rather selectively presented. The final higher taxonomic grouping used is a modified clade-based version of an earlier morphological cladistic analysis, and thus dispenses with rigid Linnaean ranks - the sub-classes, orders, and the like. Most systematists will be happy with it as an interim solution to a still-fluid situation, particularly as molecular data are not yet available. However, 29 of 81 families, mostly symbiotic, pelagic, or interstitial forms, were not in that analysis, and the authors are frank in explaining the likely instability of some placements. In this regard perhaps the commentary on every family should have made explicit comment on the respective morphological autapomorphies - the unique derived features - or lack of them (the family key has autapomorphies in bold). The article on Pilargidae covers this aspect especially thoroughly, but the article on the Pholoidae is perplexing as halfway through we discover the author wishes to abolish the group (this also leads to some overlap of genera with another family, the Sigalionidae). A number of the deepsea and interstitial polychaete families that are reviewed do not have Australian members (at least yet, as several occur in New Zealand).

Below the family level "Polychaetes & allies" may disappoint Australian field biologists eager for keys to at least genera and lists of valid names of polychaete species or even genera. There are no keys yet, apart from a family key, usually less reference to Australian representatives than might be hoped for, and no help for identification. Species lists are expected later, probably published electronically on CD-ROM and the web, and an interactive DELTA- system family key will also be published on CD-ROM. At family level the authors are largely able successfully to ignore many deficiencies in knowledge of species.

The presentations in the general polychaete section include nice summaries on zoogeography and on fossil polychaetes, but inevitably, as there are so many topics to cover, some outlines do not look beyond the obvious (for example the section on locomotion never mentions holoplanktonic swimmers or polychaete larvae). Aspects I felt were too sketchily covered were population biology (cohort analysis) and the phenomena of metamorphosis, mass swarming, and lunar periodicity. But this is a personal view; many other reviews of reproduction exist, and little has been done in Australia on these topics.

The myzostomes are retained as a class, inflated to eight mostly monogeneric families including a confusingly named pair of Asteriomyzostomatidae and Asteromyzostomatidae. The important family is the Myzostomatidae, placed in its own order, and "about 71 species of Myzostoma are recognised from Australia by the author, although only about 24 can be identified with certainty." I'm still puzzling over exactly what that statement means. This chapter does have the additional virtue of discussing myzostomes to species level, and is the first comprehensive review of the group for decades.

Pogonophora research was revolutionised by new discoveries in the 1960s, and in the last decade there has been enormous interest in the glamorous vestimentiferan vent worms which once were regarded as a separate phylum. Southward mentions the Sclerolinidae which live on rotting wood as a Pogonophora group to lookout for (in New Zealand also I suggest), but she is pessimistic that any large vestimentiferans are present in Australian waters, except perhaps the hydrocarbon-seep lamellibranchiids; the much smaller perviates do occur but as yet are unidentified. This chapter is most valuable for its general overview, although the brief family-level coverage is helpful for specifics on morphologies.

In the Echiura chapter I learnt strange facts about bonellin, a dark green pigment secreted by Bonellia viridis, and about sexual relations in bonelliids. The topics are not unrelated. Bonelliid males are dwarfs living in (!) or on the female. Bonellin is highly toxic (including to vertebrate cells), acts only in the presence of light, and may be a defensive weapon against predators and encrusting growths, but its masculinising effect when secreted by a female is one of the environmental factors determining the ultimate sex of bonelliid larvae. Exactly how this occurs, and yet in a minority of larvae sexual expression remains totally genetic, is presently unresolved.

I'm afraid the Sipuncula chapter did little to change my jaundiced view that these warty little hole-dwellers are as uninteresting as their appearance suggests. In contrast to the lively research interest in polychaetes not much seems to have been happening recently. However, I did newly learn that: sipunculans have unique scavenging cell complexes called urn cells which, like miniature jellyfish, actively swim in the sipunculan coelomic fluid while harvesting harmful bacteria; sipunculans have a characteristic planktonic larva, the aptly-named pelagosphaera, which may drift for up to 8 months in the ocean; and lastly, they have been awarded a dubious human accolade - they are rated edible (prolonged boiling and addition of a hot mustard is recommended).

It is possible to dissect every contribution, debate conclusions, and find the inevitable misspellings, minor slip-ups, and inconsistencies of any large work (such as alien serpulid Ficopomatus enigmaticus present in Australia on p. 37 but (falsely) absent on p. 189). However, nothing seriously worried me, and from my dipping through I expect errors to be few and negated by the overall high calibre of the analyses. It is marvellous to have this book, especially with the spin-off relevance to neighbouring New Zealand. Its major value for me without a doubt will be the family overviews, which I expect to be consulting frequently. "Polychaetes & allies" is a definite "must have" for everyone seriously interested in worms and, by virtue of a reasonable price, should also be attractive as a reference work for libraries and non-specialists. I would have signed off the review with the suggestion that it will be unrivalled for years to come, but as fate has it, there are two other polychaete books imminent. They will have to be very good indeed to match this one, and certainly will be hard put to find a more dramatic cover photo than the fearsome "Bobbit worm" eunicid. Clearly polychaetes are worthy of respect, as I believe "Polychaetes & allies" is also.

National Institute of Water & Atmospheric Research Ltd
P. O. Box 14-901,
Kilbirnie, Wellington, New Zealand
e-mail: g.read@niwa.cri.nz

Review 2. Dr Graham Edgar, University of Tasmania. Review reproduced with permission from: Bulletin 150 of the Australian Marine Science Association.

Despite expectations that this book would largely fill a taxonomic niche in the library. its appeal is ecological as much as taxonomic. Included in the volume is reference to almost all that is known about the life-history and ecological attributes of polychaete, echiuran and sipunculan species, as well as detail on family and higher level classification, morphology and physiology.

Given the paucity of studies conducted in Australia (as emphatically recognised in statements such as: "competition between Australian species [of polychaete] has not been studied"), the book provides a global rather than local coverage. It should therefore be equally as useful to overseas biologists as to those in Australia. Much of the ecological information presented also deserves a broader audience than the specialist polychaete worker. I found interesting snippets throughout, such as the following dry excerpt from the first family dealt with (Arenicolidae): 'In a designated part of a northern England estuary, an area was deliberately set aside for bait digging (200 m x 2 km); within weeks no arenicolids were present. Olive (1994) estimated that over 4 million worms were collected during this period.'

The monograph commences with introductory sections on the morphology, physiology, ecology and biogeography of polychaetes. These sections are comprehensive, but I was disappointed to find little explanation for an anomaly that has irked me (and others) for years - why so many polychaete taxa have such wide distributions. Off the top of my head, I can think of only two benthic crustacean taxa (the caprellid amphipod Caprella aequilibra and tanaidacean Leptochelia dubia), one inshore fish species (the mullet Mugil cephalus), no macroalgal species and no inshore mollusc species that range from Tasmania to northern Australia, yet 25 of 212 taxa included in Table 1.1 possess such wide distributions. Do polychaetes have much slower rates of speciation than other taxa? Do they have particularly effective dispersal mechanisms or broad environmental tolerances to surmount vicariant barriers that subdivide other groups? Or are wide- ranging taxa composed of morphological similar sibling species that presently go unrecognised? These questions are not adequately answered, and in fact I could find no reference to molecular studies assessing the likelihood of sibling species. In this context, I was amazed to find that Grassle & Grassle's (1976) famous study showing six discrete non- interbreeding taxa in one local North American area that would morphologically be grouped within the cosmopolitan taxa Capitella 'capitata' does not appear to have been followed up to any extent. Although 24 years have elapsed since this oft-quoted study, 'no formal descriptions of any of these species have been published to date'. I was also surprised to read (p. 9) that 'about 1140 species are known from Australian waters, and that perhaps another 20-30% remain to be described'. Although the fauna in shallow southeastern Australian waters may be reasonably well known, surely the number of undescribed species still greatly exceeds the number presently named, particularly if outer shelf and slope habitats are included?

Introductory sections are followed by a higher level classification of polychaetes and related taxa. This section is not for the timid. I came away with the view not to take it too seriously. but to leave the specialists to slug it out over the next decade or two until some consensus is reached between the morphological cladists and the molecular taxonomists. Given uncertainty introduced by continuing developments in molecular biology, the higher-level classification used will probably change substantially over the next few years.

The emphasis on monophyly during discussion of higher level classification, and elsewhere in family treatments, nevertheless seemed at odds with the polyphyletic inclusion of echiurans and sipunculans within this volume. Nowhere did I find it explained why the Clitellata (oligochaetes and leeches) were excluded, despite the universally-accepted sister group relationship with polychaetes, pogonophores and myzostomes, and much more distant kinship of all these groups with the echiurans and sipunculans. In this sense the title is slightly misleading as it should more accurately read 'Polychaetes and some of its allies'.

The bulk of the book provides general treatments of 74 polychaete families, 8 myzostome families. 6 pogonophore families, 5 echiuran families and 6 sipunculan families, supplemented by fine line drawings of whole animals and appendages belonging to at least one species in each family. These family treatments are excellent. Amongst other things, I found that one group of animals I collect frequently, and have always classified as glycerids without the slightest hesitation, are in fact members of a related family - the goniadids - a group that I had never heard of previously.

My one great disappointment with the volume relates to the ABRS decision to confine the treatment to families only. Keys to genera within each family, or a list of diagnostic features associated with the different local genera, would hugely improve the taxonomic value of the work. Given the difficulties in assigning species names to local taxa, most practising ecologists are happy with a genus name for worms collected, whereas family names are often too broad. Diagnostic information at the genus level was presumably known to the authors and could have been provided with little extra effort - an opportunity lost.

In summary, this book provides an important global reference for benthic ecologists. with a wealth of detail on diet, reproductive strategies, longevity and other life-history attributes of species within the different polychaete, echiuran and sipunculan families. It includes the best general description of the external morphology. anatomy and physiology of polychaete families worldwide that is available today, and is profusely illustrated by clear line drawings and 12 colour pages of the most marvellous worm photographs that I have seen. Nevertheless, don't yet throw away Day's (1967) 'Polychaeta of southern Africa' or Fauchald's (1977) 'The polychaete worms'. Day's work is still needed for the abundance of diagrams and detail on features useful for discriminating between species. Fauchald's book and local DELTA keys written primarily by Robin Wilson and Pat Hutchings remain essential for classifying animals to genus.

Postscript: I have since been told that my taxonomic quandaries will be solved in six months time when CSIRO/ABRS release a double CD on polychaetes - the first CD to include a key to families by Glasby and Fauchald, and the second a key to local genera and species by Wilson and Hutchings (et al.). Also, by the middle of the year the ABRS catalogue of known Australian species with relevant literature compiled by Hutchings and Johnson should be on the Web and available for download.

Under construction by Geoff Read.

Suggestions for improvements, corrections, and additions welcome. Original July 2000. Last update 17 November 2000. Please look in again soon.

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