SCUBA News 312
(ISSN 1476-8011)
July 2026

Welcome to this month's edition of SCUBA News, in which we travel to Turkey and Dominica, take a close-up look at the shell-swapping life of Dardanus Hermit Crabs and round-up the best liveaboard deals with savings of up to 50%. Plus, as always, read the diving and underwater news.

What's New at SCUBA Travel?

Dive Turkey's Turquoise Coast From the dramatic underwater canyons of Kas to the colorful reefs teeming with fish near Kalkan and the Gallipoli wrecks, diving in Turkey has something for both experienced and new divers. READ MORE Whales to Seahorses in Dominica The Caribbean island of Dominica is unlike any other, and the dive sites quiet. It is a fantastic place for independent travellers to discover. DISCOVER DOMINICA

Liveaboard Deals and Destinations

Half price on Manta madness in the Maldives and 40% off the iconic wreck dives of Truk Lagoon - just two of the offers we have for you today.

1. Blue Melody, Egypt, Northern Wrecks and Reefs. SAVE 30% August until March 2026. Choose from northern wrecks and reefs, Brothers, Daedelus and Elphinstone.



30% OFF

2. Horizon 3, Maldives. 50% Off. Hanifaru Bay Manta Madness in August and September 2026. The reef at Hanifaru Bay is shaped like a funnel. Plankton get trapped in the funnel which attracts whale sharks and manta rays - the world's largest feeding station.



HALF PRICE

3. Ilike, Indonesia. SAVE 30% on 11 day trips in the fabulous Komodo - my all-time favourite place to dive.

   

   Save Now

4. Danubio Azul, Galapagos, SAVE 18% on August trips. A small liveaboard, the Danubio Azul can accommodate up to 16 guests across its 9 cabins. Expect hammerheads, Galapagos sharks, silky sharks, tiger and whale sharks



Galapagos!

5. The Junk, Thailand, SAVE 20% - dive the Similan and Surin islands from this beautiful, teak wood, boat.

   

   More Info or Book

6. Vivax, Malpelo, Save 10%. Only one boat is permitted in the marine reserve at a time, for a remote, exclusive, diving experience.



9 Nights

7. Truk Lagoon, Pacific Master. 40% off diving the wrecks of Truk Lagoon (Chuuk Lagoon) from December 'til May.

   

   Dive Truk Lagoon

See more liveaboard deals to some of the best diving in the world - Micronesia, Philippines, Galapagos, Indonesia, Socorro, Cocos Islands...

House hunting with friends: the life of Dardanus Hermit Crabs

Hermit crabs plod about the sea-floor using someone else's shell for a home. They always use empty shells and never kill the original occupant.

Red Hermit Crab, Dardanus arrosor, taken in the Azores by Tim Nicholson

When the crab becomes to large for its shell, it looks for another. On finding a likely looking one, it tries it on for size. If it isn't pleased with the fit, or the shell is too heavy, the crab returns to its old castoff and continues it search. It may try the old and new several times before it makes its decision.

Where there is a large population of hermit crabs and a shortage of shells, the crab will accept a sub-standard home: maybe a cracked or uncomfortable shell. But in good conditions it will be very particular about the new shell it chooses. For particularly good shells, two hermit crabs will fight for possession. Some will even attack an inhabitant to steal it's particularly desirable abode. These fights don't tend to damage the combatants, probably due to complex ritualised fighting

Anemone Hermit Crab, Dardanus pedunculatus, taken in the Red Sea by Tim Nicholson

Many individuals have to settle for shells that are either too large or too small. A too small shell may result in the crab actually getting smaller after moulting, with a reduction in egg numbers. Too large renders the crab more susceptible to predators and imposes an additional energy load from the extra weight to be carried.

Sea anemone "friends"

Some of the Dardanas species of Hermit crab stick sea anemones on their shells. Sometimes the anemone assists with the process, loosening their connection to the substrate to ease transfer. The aneomone camoflauges the crab and its stinging cells may protect the crab from predators such as octopus.

Anemone Hermit Crab, Dardanus pedunculatus, taken in the Philippines
by Andy/CC BY-NC 4.0 via iNaturalist

The anemone also benefits from the arrangement. It becomes effortlessly mobile and shares the crab's meals. The crab will also defend the anemone from predators trying to eat them. It's even possible that the hermit crab feeds the anemone directly.

Night dives in temperate and tropical water

Dardanas species are nocturnal with dark-adapted eyes. Look out for them on night-dives. They live in the Indian, Pacific and Atlantic oceans and the Mediterranean Sea.

Anemone Hermit Crab, Dardanus pedunculatus, taken in Bali
by DiverCraig/CC BY-NC 4.0 via iNaturalist

Phylum: Arthropoda > Subphylum Crustacea Class: Malacostraca > Order: Decapoda (10 legs) > Infraorder: Anomura (reduced/hidden last legs) > Genus: Dardanus

Sources and References

Karplus, I. The partnerships between hermit crabs and sea anemones: an overview. Symbiosis 93, 1-15 (2024).

Chryssanthi, Antoniadou et al. (2013). Symbiosis of Sea Anemones and Hermit Crabs in Temperate Seas.

Invertebrate Zoology, Fox, Ruppert and Barnes, ISBN 0030259827

---

---

Diving news from around the World

Why a live shark is worth more than a dead one A shark is worth infinitely more alive, swimming in its natural habitat, than it is dead in a fish market. Shark fisheries are biologically incapable of being sustainable. Sharks grow slowly, mature late and produce very few young. Remove them faster than they can reproduce - which commercial fishing invariably does - and populations collapse.

California to get highest shark numbers in years as great whites head north California is set to see one of its sharkiest summers in a decade, with large numbers of juvenile great whites already on a reverse vacation from the warm waters of Mexico to cooler pastures along the western United States.

Apeks recall regulator second stages Apex have issued a product safety recall Apeks XL4, XL4+ and OCEA second stages with serial numbers from 250402212 to 260402893.

Rays employ a chemical cue to warn others of danger, new research finds Bat rays employ a well-known anti-predator strategy for bony fish but that has not been documented in cartilaginous fish until now.

Valuing conservation and natural wealth: The blue economy of manta ray watching in the Maldives Benefits of the manta ray tourism industry are estimated at over US$311 million per year.

The most common seashore litter is crisp and sweet wrappers Marine Conservation Society finds that plastic packets are the most common litter item on UK beaches, followed closely by metal drinks cans and plastic drinks bottles. If only people would take their rubbish home.

Microplastics show unexpected link to climate warming Although scientists have long worried about microplastics contaminating air, food and water, new research reveals a previously unknown threat: iny pieces of airborne plastic are heating the planet.

Sponges use photosynthesis, boosting productivity of tropical coral reefs Sponges tend to eat other organisms to get their nutrients, but a new study shows how sponges may also use photosynthesis.

Seeking swordfish, catching dolphins and whales: EU pushes to rein in driftnets The use of driftnets - nets sometimes kilometers long that drift with the ocean currents - is prohibited in the Med. Current measures though lack adequate definitions and enforcement provisions

Scavenger dolphins increasingly rely on trawlers for food in overfished Adriatic In one area 76% of fishing boats were followed, with baby dolphins learning the technique from their parents.

An island community in Thailand works to protect and revive its dugongs Koh Libong's seagrass meadows were once Thailand's largest, and a critical coastal habitat that is protected nationally. Yet, between 2020 and 2024, seagrass cover in these protected waters shrank by up to 50%.

Artificial light is keeping reef fish awake, and the effects may ripple across coral reefs Fish exposed to artificial light slept less, showed more fragmented sleep, became more aggressive and fed at unusual hours, effectively behaving as if night had turned into day.

Arabian Sea humpback whale's long-distance trip Off Oman's coast lives a small population of just over 80 Arabian Sea humpback whales. They are classified as endangered and thought to be the only humpback whale population that doesn't undertake seasonal migrations across the world's oceans.

Sao Tome declares first 2 of 8 marine protected areas The West African island nation has formally designated its first two protected sites off its coast.

First open-ocean subsea human habitat deployed in the US in 40 years Scientists to live there

31 New species discovered and described in just 14 days Experts worked in ocean midwater off Brazil at near-record speeds thanks to cutting-edge tech.

---

SCUBA News is licensed under a Creative Commons Attribution 4.0 Unported License. This means we are happy for you to reuse our material for both commercial and non-commercial use as long as you: credit the name of the author, link back to the SCUBA Travel website and say if you have made any changes. Most photos though, are copyright the photographer. Please get in touch for details.

Photo credits: Tim Nicholson, Jill Studholme, Kelly Wong Johnson, Pete McGee/CC BY-NC 4.0, DepositPhotos, divebooker.com

UNSUBSCRIBING
Visit {?$optout_link?} to remove yourself from the mailing list. Any problems contact [email protected].

ADVERTISING
Should you wish to advertise in SCUBA News, please see the special offers at
https://www.scubatravel.co.uk/newsad.html
Other advertising opportunities are at
https://www.scubatravel.co.uk/diving-advertising.html

CONTACTING THE EDITOR
Please send your letters or press releases to:
Jill Studholme
SCUBA News
The Cliff

DE6 2HR
UK
[email protected]

---

SCUBA News (ISSN 1476-8011)

Every month we send out a free newsletter featuring the best diving areas, underwater life, diving book reviews and interviews with authors. To receive this please fill in your e-mail address below. For an archive of previous issues see the SCUBA News page.