Bookshelf: Manta

Manta: Secret Life of Devil Rays – Guy Stevens & Thomas Peschak

I found this book to fill a significant gap in my manta ray knowledge, which was (to be honest) virtually nonexistent. Author Guy Stevens is founder of the Manta Trust and a Save Our Seas project leader, and has spent 15 years in the Maldives studying these enormous, charismatic elasmobranchs. The Manta Trust co-ordinates global manta research efforts, with the aim of protecting and conserving mantas and their relatives.


The photographs in this book are by Thomas Peschak, co-founder of the Manta Trust, with whose extraordinary work you should be familiar. (If not, look here, here and here.)

Everything you might want to know about mantas is here, without being glib about the fact that there is still much we do not understand about these animals. The text covers their biology, life histories, threats to their survival, an identification guide, and numerous accounts by field scientists who study mantas and devil rays. (It was hard not to be envious reading some of the day-in-the-life bits!)

This is a beautiful, substantial book. Get it here.

Bookshelf: The Annotated Old Fourlegs

The Annotated Old Fourlegs – Mike Bruton (and Prof J.L.B. Smith)

This is a beautifully designed and produced annotated version of Old Fourlegs, J.L.B. Smith’s account of the discovery and positive identification of a living coelacanth in 1938. Wide margins around the original text allow Mike Bruton to bring Old Fourlegs up to date with additional scientific information, as well as photographs, explanations, and other curiosities.

The Annotated Old Fourlegs
The Annotated Old Fourlegs

Old Fourlegs describes the months in 1938-1939 during which Smith confirmed the identity of the coelacanth with the essential assistance of Marjorie Courtenay-Latimer of the East London Museum. Ms Courtenay-Latimer acquired a fish specimen from a trawler captain, and, realising that it was an exceptional find, contacted Smith, an ichthyologist at Rhodes University. A rollercoaster of events – which involved the chartering of a South African Airforce plane and stretched all the way to then-Prime Minister D.F. Malan – was set in motion. Old Fourlegs is a surprisingly emotional, thrilling book by a man deeply invested in his work, and whose world was upended by the discovery of living coelacanths in the waters of the southern Indian Ocean.

It is also a book of its time, and today’s readers will find some parts by turns mystifying, and others offensive. The offensive bits – including lionising D.F. Malan, who, with his government, laid the foundations of the edifice of South Africa’s apartheid legislation – remain so, but Bruton’s annotated version provides context for readers unfamiliar with the history.

The book concludes with an examination of the cultural legacy of the coelacanth, which is disproportionately significant. The fish also has deep and wide links to South Africa and our research and diving community. If you have the appropriate (very deep diving) qualifications, you can dive with them in Jesser Canyon in Sodwana Bay. If you’ve never seen a video of one of these magical animals in motion, I encourage you to hit up youtube. Watch with the sound off for best effect.

Get the book here (South Africa), here or here. This is a volume you should read in hard copy, not as an ebook.

Bookshelf: Between the Tides

Between the Tides: In Search of Sea Turtles – George Hughes

I have been late in coming to this book, which was published about five years ago. George Hughes is a world-renowned, South African turtle scientist whose work has done much to ensure protection for sea turtles in the southern Indian Ocean. He was the guest speaker at an event held at the Two Oceans Aquarium to celebrate the release of Yoshi, the loggerhead turtle who spent over 20 years at the aquarium and is now powering along the Namibian coastline in rude health.

Between the Tides
Between the Tides

Dr Hughes was CEO of the Natal Parks Board and then Ezemvelo KZN Wildlife, but Between the Tides relates his early career as a student looking for turtles along South Africa’s wild north east coast, in places that today support thriving dive and fishing charters. His legacy of turtle research continues.

Turtle surveys were conducted around Madagascar, the Comores, Reunion, the Seychelles, and on the Mozambique coast. The fact that the iSimangaliso Wetland Park now exists, offering a protected and well-regulated breeding environment for three species of turtles (loggerhead, leatherback and green – discovered there in 2014) is thanks to the early and persistent work of Dr Hughes and his colleagues. Turtles were first found nesting on this piece of coast in 1963, when it was still completely wild and mostly neglected by the authorities. In this book Dr Hughes recounts the development of the tagging program that he started, in which over 350,000 hatchlings were flipper tagged and/or marked over a period of 31 years.

Only about two out of every 1,000 hatchlings survive to return to the area in which they hatched, to breed. Female loggerheads are estimated to reach maturity around the age of 36 years, during which time they navigate an ocean of threats. This makes every surviving hatchling incredibly valuable.

The recovery of the number of loggerheads, in particular, has been quite spectacular, with more modest but noticeable gains in the leatherback population. More recently, as technology has allowed it, satellite tagging has shown their movements around the Indian ocean

If you find a baby sea turtle on the beach (this is the time of year when they start washing up), here is what you should do. The most important thing is to keep it dry, and to contact the aquarium as soon as possible.

Dr Hughes also discusses the sustainable use of sea turtles (for example, for food), something which I’d never thought about and which for that reason is fascinating – and very challenging to come at with an open mind, and appreciating the viewpoints of a scientist who has been steeped in turtle research for most of his life.  This is an excellent, proudly South African marine science book, written to be accessible even to those who aren’t turtle fanatics a priori. Highly recommended.

Get a copy of the book here (South Africa), here or here.

Hunting rockcod and moray eel in Sodwana

This is a really cool bit of behaviour that I filmed on a dive to Pinnacles on Two Mile reef while we were in Sodwana last September, and one of my favourite things of all that we saw. A malabar rockcod (Epinephelus malabaricus) – as identified by our dive guides – in dark hunting colours, patrols the reef ahead of a honeycomb moray (Gymnothorax favagineus). At the time I didn’t know what was happening – it looked as though the eel was stalking the grouper – but it turns out to be more complicated and more interesting than that. I had filmed a subset of a total pattern of behaviour, in which the moray and rockcod (from the family of fish also called grouper) were hunting co-operatively.

A researcher at a Swiss university discovered in 2006 that coral groupers seek out giant moray eels (both of these species live in the Red Sea), summoning the eels from their dens with a vigorous shaking of their bodies. The fish and the eel then swim together looking for prey , a deadly tag-team of hunters. The groupers are fast in open water, but the eel can get into crevices to flush out prey. It is this behaviour, executed by a different type of eel and a different type of grouper, that I saw in Sodwana.

The scientists reported that the groupers use a head-stand signal, combined with a shaking of their bodies, to indicate the location of hidden prey to the eels. When the eels see this, most of them swim towards the grouper, and flushed out the prey.

You can read more about the study that revealed the extent of this behaviour here, and the actual paper reporting the research here. The scientists also discovered two other species with complementary skills that hunt co-operatively, on the Great Barrier Reef this time: the coral trout, and octopus.

Moray eels look incredible when they swim freely across the reef. Here’s one doing just that, in the Red Sea.

On the reef in Sodwana

We wrap up the videos from Sodwana with a couple of clips showing everyday life on the reef. Both these videos were filmed on a beautiful dive on Pinnacles, Two Mile Reef, which was strangely not marred by an absolute circus of an Open Water course that was being conducted in the vicinity. (Pinnacles is a popular training site.) Despite antics which included two people’s weight belts coming loose at the same time, we were able to stay away from that chaos and to enjoy some incredible reef life. (Perhaps I will share some footage of the weight belt fiasco when a suitable amount of time has passed.)

Clown triggerfish having a munch
Clown triggerfish having a munch

First up, a clown triggerfish (Balistoides conspiccillum) going about his business on the reef. These fish are fantastic looking, and if you ask Sophie nicely, she will show you the hand signal for them, which requires both hands to be free.

Here’s pair of barred filefish (Cantherhines dumerilii) at Pinnacles:

Schooling in Sodwana

In addition to lots of bluebanded snapper, we saw other schools of fish while we were diving in Sodwana. A calm approach with minimal body movement allows one to get quite close to them. Here, a school of lunar fuslier (Caesio lunaris) are led by a lone yellowback fusilier (Caesio xanthonota), filmed on Two Mile reef.

We also saw this school of handsome humpback snapper (Lutjanus gibbus) over Pinnacles on Two Mile Reef.

Reef life on Seven Mile in Sodwana

While we were in Sodwana in September, one of the dives I did was to Seven Mile Reef, which is further out and less busy than Two Mile. The dive was also slightly deeper than the Two Mile dives we did, which meant there was less surge and conditions were a bit easier all round.

We saw some lovely fish behaviour, and I’ll share two short videos taken with a new camera (more on that another time) to illustrate it. First, a redfang triggerfish (Odonus niger) slides its body into a crevice in the reef as I approach, to hide. This is typical behaviour when these fish are nervous.

Here’s a semicirle angelfish (Pomacanthus semicirculatus) concentrating very hard on feeding. These fish look like nothing so much as gorgeously decorated sheets of A4 paper with fins and a snout!

Snapper in Sodwana

Snapper are one of my favourite coral reef fish to dive with, because sometimes they’ll allow you into, or very close to, the dense schools they form over the reef. This must be what it feels like to be a fish, albeit one that breathes loudly and blows bubbles!

We saw these bluebanded snappers (Lutjanis kasmira) on a dive at Seven Mile Reef in Sodwana, last September. Notice the pair of Moorish idols (Zanclus cornutus) at the start of the video.

 Here’s another school of snapper we came across shortly after the first one. There are often other kinds of fish, including other types of snapper, in the school.

The Reef Guide is a good place to learn more about, and identify, the fish you see on dives off South Africa’s south and east coasts.

Map puffer in Sodwana

This handsome, uncommonly seen map puffer (Mappa puffer – honestly) swam towards me on Seven Mile Reef in Sodwana, and hung out for a minute or two while I took his picture. His patterns look a bit like a circuit board, don’t you think? These fish are solitary and quite shy, usually staying near overhangs in the reef.

The Reef Guide is a good place to learn more about, and identify, the fish you see on dives off South Africa’s south and east coasts.

Cleaning stations in Sodwana

A barred rubberlips at Pinnacles
A barred rubberlips at Pinnacles

A barred rubberlip (also known as a red-lined sweetlip, Plectorhinchus plagiodesmus) at a cleaning station on the reef at Pinnacles on Two Mile reef in Sodwana. It was a surgy day, but if you look closely you can see the bluestreak cleaner wrasses (Labroides dimidiatus), with grey, black and blue stripes, swimming in and around the rubberlip’s gills. The rubberlip opens his gill slits so that the wrasses can eat parasites and remove excess mucous, maintaining good health for the fish.

We also saw this yellowfin surgeonfish (Acanthurus xanthopterus) at a different cleaning station, on Seven Mile Reef, also being serviced by bluestreak cleaner wrasses. These fish are usually blue-grey or even brownish, but at cleaning stations they often change colour to a light blue-grey (as this fish has).

Here’s a busier cleaning station, on another dive at Pinnacles. There are two yellowfin surgeonfish, one of whom seems to get a bit cranky with the cleaner wrasses at the end of the video, as well as a crescent tail bigeye (Priacanthus hamrur) at the beginning. The spotted unicornfish (Naso brevirostris) should be easy to spot; their colouration here is much darker than in my fish ID book.

The Reef Guide is a good place to learn more about, and identify, the fish you see on dives off South Africa’s south and east coasts.