Aug 2, 2008

Fishes and more at St. John's Island

Today we saw lots of fishes at the reefs of St. John's. The water was teeming with little blue Tropical silversides (Atherinomorus duodecimalis). They kept disturbing the water surface making it difficult to photograph submerged creatures. And to make things even more difficult, they were attracted to my torch!
There were lots of Blue-spotted fantail rays (Taeniura lymma)! Of course, the little silversides just messed up the photos.Finally at sunrise, I managed a clear shot of this beautiful animal. There is a broad skin fold under the tail, that's why it is called the fantail ray. Like other rays, it has one or two venomous spines near the middle of the tail. The spines are used to protect itself and not to capture prey. As long as we are careful not to step on them, these fishes are harmless.
Hiding among the corals were several of these blue fishes. I don't know what they are, probably some sort of damselfish (Family Pomacentridae).This fish stuck its face into a crevice, probably thinking if it can't see me, I can't see it. I'm not really sure what it is, but it could be a Longspined scorpion fish (Paracentropogon longispinis).This Painted scorpionfish (Parascorpaena picta) was right out in the open but so well camouflaged that I almost missed seeing it.

Scorpionfishes have stout spines on the dorsal fins act like hypodermic needles, injecting venom that can be excruciating to humans. A scorpionfish uses its venom only for protection and not to catch or kill prey. The scorpionfish is not aggressive and prefers to hide or swim away, using its venom only as a last resort. The best way to avoid being stung is simply not to disturb or touch one.
This scorpionfish-lookalike was also seen. It is NOT a scorpionfish and belongs to the grouper family (Family Serranidae). It is the harmless False scorpionfish (Centrogenys vaigiensis). If you compare it with the Painted scorpionfish, the False scorpionfish has small eyes and nose flaps.Among the thickets of brown sargassum seaweed was this ball of Lined eeltail catfishes (Plotosus lineatus). This is another fish that should be left alone as they can sting.
This White-spotted rabbitfish (Siganus canaliculatus) can also sting if they are handled. Although the Stonefish (Synanceia horrida) was seen before in the past, we fortunately didn't encounter him today.

The reefs were also teeming with crabs, especially the Brown egg crabs (Atergatis floridus) and Red egg crabs (Atergatis intergerrimus), and colourful swimming crabs (Family Portunidae) of all kinds.
There were also lots of octopus out busy hunting.Another fascinating hunter of the shores at low tide is the Marine spider (Desis sp.). This one seemed to have caught something. These spiders hide in crevices at high tide and emerge at low tide to forage.

Besides the reef creatures, St. John's also has other intertidal habitats with interesting animals.The swimming lagoons of St. John's also has some Common sea stars (Archaster typicus). There were also lots of busy bulldozing moon snails (Polinices sp.) and lots of little gobies and snapping shrimps.St. John's is one of the few places where you can still see the beautiful lilac Land hermit crab (Coenobita cavipes). This one is using the shell of a land snail! They are only active at night and disappear into hiding places in the day.

St. John's also has a small patch of mangroves. But we didn't have to energy to explore further today.

Vyna shared about her crinoid and other sightings on her can you sea me blog

1 comment:

peizee said...

tt's an awesome blue octopus.