The Mozambique Ghost Goby (Pleurosicya mossambica) is also known as the Common Ghost Goby, the Toothy Goby and the Many-host Goby. As can be seen in the images in the post, they are found on numerous hosts. They are however easiest to spot on Bubble Corals because of the contrast between the light colored corals and the pinky color of the goby. They have a commensual relationship with their hosts, or in other words the Goby benefits from the protection of the host and the host is unharmed.
The Mozambique Ghost Goby has a transparent body with a set of prominent red and yellow ringed eyes which are angled at roughly 45 degrees giving them a very good field of view. The body behind the eyes is a reddish colour and there is a red line running back to the caudal area with series of darker brown or reddish brown bars down the side. Under magnification as seen below, the scales are lightly edged and there are black and red dots on the head and body.
There may be an element of sexual dimorphism in that the larger gobies often have a series of white marks interrupting the red line down the back which can be seen in the image above. When we do see a pair together the larger specimen usually has these white marks whereas the smaller one does not. This could just be coincidence however and it could be that all adults have the marks over a certain size and further investigation is necessary.
The translucent body allows the background colour to come through the fish enabling them to blend into the background and works as an effective camouflage. Although they are not well camouflaged on bubble coral, they are extremely difficult to spot on darker corals.
To allow them to attach themselves to the corals which are often in high current areas, their pelvic fins have evolved into sucker like appendages which give them a firm grip. Further aiding in their camouflage are their gills which are set lower down towards the underside of the body, making it more difficult for predators to spot the moving gills. Mozambique Ghost Gobies have a proportionally elongated body and large eyes which allow them to spot passing planktonic matter. They grow up to 3 cm in length.
MOZAMBIQUE GHOST GOBY IN THE WILD
Because of their size which is usually around 2cm , the Mozambique Ghost Goby is very difficult to spot on anything else other than bubble coral. At night however when their eyes reflect light they are easier to find on some of the larger hard corals. They are remarkably alert to an approach by divers and usually they skip off if one gets too close. This makes it difficult to approach them to photograph.
We have found them on a variety of hard corals as well as on an Egg Cowrie as pictured in the image above. In the image below we spotted a specimen on the mantle of a clam and one has to look carefully on the left of the mantle to spot the specimen in the image below. They have also been recorded on sponges and algae.
The literature on these fish states that they are usually singular , however we often find pairs and even groups of up to five in close proximity.
The Mozambique Ghost Goby , is found across the Indo west Pacific area from East Africa to Southern Japan, south to the Great Barrier Reef and east to the Mid Pacific Islands. We have seen them from 8 meters down to 20 meters in Tanzanian waters.
The Mozambique Ghost Goby feed on planktonic matter passing by in the water table. They are also known to eat mucus and polyps off of the corals.
Research indicates that similar small gobies are able to change sex during their lives and one assumes that this will be the case with the Mozambique Ghost Goby. Both sexes seem to have both male and female organs which can be triggered to become dominant in the other smaller gobies. These potential changes probably depend on social cues. The eggs are laid demersally or in other words directly on the substrate. Little seems known of their life cycle.
Mozambique Ghost Goby are not commonly kept in aquariums.
MOZAMBIQUE GHOST GOBY CLASSIFICATION