Under The Microscope

THE ROOKPOOL FISHES OF NEW ZEALAND, by Chris Paulin and Clive Roberts; National Museum of New Zealand; $49.95 1993

This is a handsomely presented, large hardback volume, printed on high-quality paper with numerous colour illustrations, and covering 83 "rockpool" fishes. Most are splendidly illustrated and authoritatively described by two of the same people who brought us that indispensable reference for the serious student of fishes, New Zealand Fish: A Complete Guide.

I opened this book expecting to see lots about blennies, triplefins, topknots, pipefishes, clingfishes. seahorses and the like; and was not disappointed. The book adds much to the knowledge of these species, which have received very superficial treatments in most earlier fish books.

Many species are difficult to identify because of their similarity to one another. Also, in some cases, males, females and juveniles of the same species all are differently coloured, and some change colour at spawning time. The authors have done much to sort this out, to the benefit of marine biologists and keen laypersons of all ages.

However, these only take up just over half of the book; the rest is "surge zone fishes". This seems an odd extension of the book's scope beyond its title; but more than this, the definition of a rockpool fish also is pushed to the limit. Tarakihi, for example, are included because "juveniles are occasionally found in large rock pools", and john dory because they "may occur in rockpools as a transient species between tides. (According to this logic, I would also have expected to see garfish, jack mackerel, koheru, snapper, barracouta and others.)

The book hardly adds to the knowledge of these species, which would better have been omitted in order to enable a cheaper, real guidebook to rockpool fishes. This would find a wider market without having to compromise its scientific impeccability.

Mike Bradstock is a former fisheries biologist.