Field Guide to Manta & Devil Rays of the World

This field guide by Guy Stevens and his colleagues is a fantastic read – it is a thorough and
comprehensive reference to assist with the identification of mobulid rays and the species they
form symbiotic relationships with. The detailed species accounts consist of key features, range
maps, behavioural descriptions and underwater imagery for each manta and devil ray species,
which will be an invaluable resource to anyone with an interest in marine biology, regardless
of their scientific background.

As many will already be aware, all manta and devil ray species worldwide are currently
threatened with extinction, with the giant oceanic manta ray listed as endangered by the IUCN,
and the smaller reef manta ray listed as vulnerable. The largest threat to mobulid species is, of
course, humans, with a landmark global study led by the Manta Trust and a network of
international experts attributing 87% of mobulid deaths worldwide to small-scale fisheries. The
Manta Trust has taken a three-pronged approach to conservation: research; education; and
collaboration – and this field guide perfectly encompasses all three.

Over the course of just under one hundred pages, the authors systematically work through an
introduction into mobulid rays, their identification, and species accounts, before ending on
research and conservation management. Their invaluable knowledge is paired with fantastic
photographs and wonderful illustrations by Marc Dando. The chapter on identification contains
over a dozen ways to assist with identification of mobulid rays and their associated species,
whether the animal itself is seen alive in the ocean, dead at fishery landing sites, or even illegal
gill trading (it is important to note that in the months after this guide was published, manta and
devil rays were uplisted to CITES appendix I, making all international commercial trade in
these species and their parts prohibited).

The need for mobulid conservation is a theme which runs throughout the guide, with a major
focus on fisheries and international trade, particularly in the targeted capture of manta and devil
rays for their gill plates, and the accidental capture of rays as a bycatch, where the animal is
often unable to recover. Despite this, the guide contains a bycatch avoidance and best practice
section, which clearly explains how to avoid the accidental catch of mobulid rays, and what to
do (and not do) in the instance of a ray being caught. The authors reflect the Manta Trust's
sentiments in the idea of education being one of the best forms of conservation: if enough
people who spend time near or around these species engage with informed writings like these,
the more able we will be to allow the populations of these magnificent species to recover.

If you are interested in manta and devil rays, or planning to spend any time with these
fascinating creatures: whether that is through research; conservation; diving; or simply
spending time in or around their habitats, this book should be welcome reading. Filled with
expert information from scientific collaboration, you need no prior knowledge to enjoy this
guide, although I am sure it will contain new information to any reader, no matter your
background.