Tag: Invertebrates

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Racing stripe flatworm

Racing stripe flatworm swims over Discosoma coral

Racing stripe flatworm {Pseudoceros bifurcus} on Discosoma sp. which is a corallimorph. There is a contrast between the colours of the flatworm and the coral. Malapascua, Philippines. November

Location & date

Chocolate Island, Malapascua, Philippines. 16th November 2014

Subject

The racing stripe flatworm Pseudoceros bifurcus is a ‘say what you see’ species. The distinctive white stripe with dark border easily identifies this species. This example has a cut, possibly a bite mark, on one side. This particular flatworm was moving fairly quickly over coral. Species of the Discosoma genus are corallimorphs, with large wide oral discs. The discs are often brightly coloured, as in this specimen. The colour comes from symbiotic algae.

About this image

At first glance this looked like a fast moving nudibranch. In tropical waters, flatworms are often similar in look to sea slugs. Often brightly coloured and slug-like in appearance, they move sinuously across the substrate. In this case I saw this racing stripe flatworm was moving across a particularly photogenic coral. The length of the flatworm made it difficult to get the whole thing in frame.

Camera setup

Nikon D800, 105 mm Nikon lens in a Nauticam NA-D800 housing with two Inon Z240 strobes.
ISO 100, f/22, 1/125 sec

More like this:

Marine invertebrates photography (on this site)

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Fluorescent coral polyps

Image under ultraviolet showing fluorescent coral polyps

Polyps of a reef building coral {Pocillopora sp.} fluoresce green under ultraviolet light.

Location & date

Wadi Lahami, Red Sea, Egypt: 23rd June 2014

Subject

Corals of the Pocillopora genus are some of the fastest growing on the coral reef, and are therefore an important part of the reef building process. They tend to be found in shallow water – this one was at about 5m on the reef edge. The fluorescent coral polyps contain zooxanthellae – symbiotic algae which provide the energy for growth through photosynthesis.

About this image

This was my first attempt at Ultraviolet (UV) fluorescence underwater photography. I was diving with Red Sea Diving Safari,  on a shallow night dive close to shore on Torfa house reef. Apart from creating eyecatching ‘different’ photographs, my interest in fluoro photography was mainly the conservation aspect. This technique is used by conservationists to assess the health of coral reefs. Healthy coral fluoresces at a different intensity to less healthy coral. By comparing the same species on healthy reefs and unhealthy reefs, conservationists can build up a pattern and start to predict when reefs are under stress, before mass bleaching events occur.

Camera setup

Nikon D800, 105 mm Nikon lens in a Nauticam NA-D800 housing with two Inon Z240 strobes (each with blue filter), Nauticam Super Macro Converter with orange filter.
ISO 100, f/14, 1/30 sec

More like this:

Red Sea portfolio gallery (on Toby Gibson Portfolio site)

Coral reefs portfolio gallery (on Toby Gibson Portfolio site)

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Double-spined or banded sea urchin

The Double-spined urchin {Echinothrix calamaris} is fairly common in the Philippines and lives in rocky or coral crevices. The common name comes from the two distinct types of spine. Also known as the banded sea urchin. Malapasuca, Philippines, November.

The double-spined or banded sea-urchin Echinothrix calamaris

Location & date

Malapascua, Philippines: 14th November 2014

Subject

A close-up of the banded (or double-spined) sea urchin Echinothrix calamaris showing the translucent anal papilla (which looks like a glitter ball). The banded spines can clearly be seen, as well as the five naked areas of test forming a blue star pattern, which is a distinguishing feature. The banded sea urchin is distributed throughout the Indo-Pacific region, and generally only comes out from rock or coral crevices during the night. However this individual was out in the open during the daytime. The smaller spines can produce a nasty sting.

About this image

I often see these sea urchins, even during the daytime, but had never really stopped to look really close up. I have usually been trying to avoid them, while photographing other species. I never noticed the beautiful pattern formed by the test and spines.

Camera setup

Nikon D800, 105mm in a Nauticam NA-D800 housing with two Inon Z240 strobes
ISO 100, f/16, 1/100 sec

More like this:

Malapascua 2014 Portfolio gallery (on Toby Gibson Portfolio site)

Gallery of Philippines wildlife (on this site)