For a fresh amateur SCUBA diver the variety of fish life in the Indian Ocean is all but numbing the senses. But soon enough you see there is some logic to the Darwinian evolutionary madness, and you want to know what all those fish really are - that's when you start looking for field guides. Having bought, and quickly forgotten, several I finally found this one, which has since stayed a true and trusted travel companion to Thailand and the Maldives.Debelius Indian Ocean Reef Guide (and indeed its sibling covering the Red Sea) has several real strengths and no significant drawbacks - except perhaps weight, 0.9 kg is just more than marginal if you want to travel light.
The choice of species included is accurate - unlike some other guides, you have a good chance of finding what you are looking for. Most of the species are fish (including sharks and rays), but also arthropods (shrimps, lobsters), molluscs, flatworms, corals, sea stars, sea urchins, reptiles and a few mammals are covered to a degree, though far from fully. Naturally they are all sorted according to families and species. All in all something like 800 - 900 species.
The photos are crisp and clear, portraying the specimens in a way so you can recognize them. A small number of photos are full page, but the majority are appr 9X6 cm (there are three descriptions to a page) with a few additional smaller ones illustrating varieties.
The descriptions are generelly brief, of course, but well written. Scientific names are always included.
Spread through the book are also almost 20 "picture stories", 1 - 4 pages each on subjects such as "Chagos", "Whales off Sri Lanka" and "Sex on the reef".
The book is structured according to scientific classification. The table of contents is clear, using colours to visually delineate similar groups - even if this makes parts of the table somewhat hard to read.
At the end are two alphabetic indices, one for scientific names and one for common names, and here is my one real source of gripe about the book. The indices are set in a very small and condensed type face, making them really hard to read unless you have perfect eye sight. The index on common names is not as complete as it should be, listing only the exact name but not parts or permutations of it (e.g. "Crocodile needlefish", but never "needlefish"; "Common cleaner wrasse", but not "cleaner wrasse" which you would probably be searching for). Also, common names are not so common as one might think - several fish are known under two, some even three, english "common" names in the world - Debelius only ever lists one.
To sum it up: weight and indices are very minor drawbacks, I simply will not leave this guide at home when heading for tropical diving!
