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Nudibranchs and the fabulous Spanish Dancer (Hexabranchus sanguineus)

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Every good Dive Master/photographer has a problem. They must look after their clients while still taking pictures. They have no time to vary the depth of focus, no time to change camera settings; their dive clients must always come first. Colin Ogden of Amoray Diving at Sodwana Bay solved the problem by shooting nudibranchs, and his study of these amazing creatures has become a passion. I spent a spellbinding evening with him learning about them.

Nudibranchs come in brilliant colours, with fabulous markings, and they can vary in size from 1mm to 600mm. They are primarily carnivores and will eat hydroids and other species of nudibranchs but most of them feed on sponges; all of which are animals. A few will eat algae or seaweed. They feed where food is available so they frequent areas where coral growth is limited; even the cold Northern European waters harbour these colourful sea slugs and nudibranch hunting has become a global passion.

Nudibranch means exposed gills. Hexabranchus, for example, has six sets of exposed gills. All but two nudibranchs are called by their Latin names. The scientific community frowns on them being given common names so the study of these creatures is not for the faint-hearted.

Most of them breath using the exposed bunches of gills on their backs, and their sensual organs are contained in a pair of rhinophores, on the front of their heads. These look like horns. All are hermaphrodite, with both male and female sex organs, which are always on the right hand side, below the neck. These can be expelled to accommodate a large meal, and then re-ingested. All of them are poisonous to fish, and a single nudibranch can kill an entire aquarium full of fish if it becomes stressed and lets off a toxin. This occasionally benefits the palatable flatworm. He sometimes mimics the shape and rhinophores of the poisonous nudibranch, escaping predators and protecting himself.

 

 

 

 

 

 

There is even a species that farms algae in its gills.  It is long and thin and has many sets of gills or cerata which he uses to collect algae. You will sometimes find it spread out along the top of the reef on a sunny day, cerata exposed to catch the sun so the algae will grow faster.

The spectacular Spanish Dancer (Hexabranchus sanguineus) is one of the very few nudibranchs that goes by its common name. They grow up to 600mm long, so are clearly identifiable. “They are nocturnal animals in our waters, so we rarely spot them in Sodwana Bay. However, we found two on the point of mating on Seven Mile in broad daylight. They lined up neck to neck, and then they exchanged sperm, fertilising each other. After five or six days each lays a long egg ribbon in a continuous circle, and you can see these on the reef looking like soft rosettes.

 

 

 

 

 

 

They are normally pink, reddish or orange. These ribbons are preyed upon by other nudibranchs of the Favourinus family and the survivors hatch into tiny nudibranchs that look nothing like their imposing parents.

Other species lay egg ribbons that hatch into tiny veligers, which are a larval stage, and they can float around in the ocean, following currents for months on end. When they sense that there is a food source, they will descend onto the reef and metamorphose into small nudibranchs. The study of these creatures is still in its infancy, although some were described as early as the 1700s, but they are fascinating creatures, and there are still many unnamed and quite rare species in our waters. Once you know what you are looking for, you can find them almost everywhere.


Words: Jill Holloway

Pictures and technical data: Colin Ogden, Amoray Diving

Copyright Ocean Spirit 2017 – www.osdiving.com

Jill Holloway lives in Mauritius and at Sodwana Bay Isimangaliso Wetland Park in South Africa. A PADI qualified Nitrox diver with over 1,500 dives, she is a passionate observer and preserver of the marine environment, and has a database of over 35,000 fish pics and hundreds of Gopro videos on fish behaviour, which she shares with her readers.

Gear Reviews

Gear Review: Fourth Element 3mm Neoprene Gloves (Watch Video)

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In a video shot exclusively for Scubaverse.com, Jeff Goodman reviews the 3mm Neoprene Gloves from Fourth Element.

For more information, visit www.fourthelement.com

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Veterans take part in Hadrian’s Wall trek to raise funds for their ‘Red Sea family’

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A group of veterans from Scuba Diving rehabilitation charity Deptherapy have pledged to take part in a 40 mile expedition-style trek along historic Hadrian’s Wall this July to raise funds for the staff at Egyptian dive centre and resort Roots Red Sea.

The dive centre in El Quseir has been closed since the start of the Covid-19 Pandemic last Spring and with Egypt now on the red list for UK travellers it is unlikely to be able to re-open in the near future. UK couple Steve and Clare Rattle, who own Roots Red Sea, have been supporting the 16 staff of the dive centre and their families but faced with an ever increasingly uncertain future, the Deptherapy beneficiaries wanted to add their support too.

Roots Red Sea is Deptherapy’s home from home in Egypt and the location where the charity’s majority of overseas training courses and expeditions are held. The facilities at the Egyptian dive centre and resort are a perfect fit for the charity offering an ideal combination of self-contained and fully adapted accommodation, as well as a team of highly trained staff.

Deptherapy normally runs 2-3 trips to Roots Red Sea each year but recent and planned trips continue to be a casualty of Covid. For the time being, training has shifted to UK waters, but their Egyptian family is never far from the minds of the Deptherapy Team.

“We’re hoping to raise £3,000 for the staff at Roots to support their families due to hardship caused by the pandemic,” explains Tom Oates, Deptherapy Divemaster, Ambassador and former Scots Guard.

“Deptherapy has been a lifeline for so many of us beneficiaries and an essential part of that journey has been our scuba diving adventures at Roots Red Sea. We view the staff at Roots as part of our extended families. They have become close friends. The welcome, service and care we are shown is unbelievable but now it is our turn to give something back. The staff at Roots have given us everything and have helped to save and change our lives. Now, they need our support.”

“This is an amazing endeavour from the guys at Deptherapy,” says Steve Rattle, who is organising the logistics of the trek which is planned to stretch over several days. “We have supported the charity for many years; it’s always been a delight to have them come to Roots and to see them really benefit from the experience. Now the tables are turned, and it is the families of Roots that are in need of help. It is really humbling to have Team Deptherapy now raising money for them. Awesome effort!”

The fundraiser is scheduled to take place from 12th -16th July 2021 starting from Heddon on the Wall in the east to Lenercost in the west. The route has been designed to take in a variety of features including many historical sites such as the Roman Army Museum at Greenhead.

Please give generously to sponsor Team Deptherapy in their quest to raise £3000 for the families of Roots Red Sea at the special JustGiving Page: www.justgiving.com/crowdfunding/rootsredseafundraiser

For more information about the work of Deptherapy and Deptherapy Education visit www.deptherapy.co.uk.

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Competitions

Explore the amazing triangle of Red Sea Reefs - The Brothers, Daedalus and Elphinstone on board the brand new liveaboard Big Blue.  With an option to add on a week at Roots Red Sea before or after. 

Strong currents and deep blue water are the catalysts that bring the pelagic species flocking to these reefs. The reefs themselves provide exquisite homes for a multitude of marine life.  The wafting soft corals are adorned with thousands of colourful fish. The gorgonian fans and hard corals provide magnificent back drops, all being patrolled by the reef’s predatory species.

£1475 per person based on double occupancy.  Soft all inclusive board basis, buffet meals with snacks, tea and coffee always available.  Add a week on at Roots Red Sea Resort before or after the liveaboard for just £725pp.  Flights and transfers are included.  See our brochure linked above for the full itinerary.

This trip will be hosted by The Scuba Place.  Come Dive with Us!

Call 020 3515 9955 or email john@thescubaplace.co.uk

www.thescubaplace.co.uk

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