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Leslie

Critter Expert
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Everything posted by Leslie

  1. Teresa Zubin's site is usually pretty good. As far as I know there are 2 species with that rounded triangle on the hump - venustus & speciosus. The small dark spots on venustus are royal or dark blue. On specious they're reddish-purple, also the saddle is redder as well. Ancylomenes venustus - http://www.starfish.ch/Fotos/crustaceans-G...s-venustus5.jpg Ancylomenes speciosus - http://www.starfish.ch/Fotos/crustaceans-G...-speciosus1.jpg
  2. It would be more accurate to say that everyone gets confused with these, Steve! This group of species is a royal pain but fun. Periclimenes is being split into a number of smaller genera and new species with a saddle on the abdominal hump are being described all the time. I think this is Periclimenes venustus which was just moved into the new genus Ancylomenes.
  3. Before the lights came on? I'll pass the info onto Dr. Caldwell.
  4. According to the Australian Museum's stomatopod page, species either carry them around like the peacock or cement to the wall of their burrows http://crustacea.net/crustace/stomatopoda/index.htm
  5. Interesting reply complete with id -- "Thanks. The species in the photos is Acanthosquilla multifasciata, a fairly common stomatopod that lives in sand burrows. The red color are the ovaries packed with eggs visible through the transparent cuticle. If you look at the first photo with the female on her back, you can see some white bands on her thorax. These are cement glands that only develop when the female is ready to lay her eggs. They provide the cement that holds the egg mass together. This species almost never leaves its burrow and is quite clumsy on the surface. I suspect she was disoriented and was trying to make a swimming escape, although another possibility is that she was distressed by a failed attempt to lay her eggs. When something goes wrong physiologically, stomatopods often leave their burrows. Again, thanks for showing me the photos. It is rare to see the species - especially a gravid female." The white bands that he refers to are the 3 bands that stretch between the 3 pairs of legs. To me the clump of eggs on her back supports the idea of a failed attempt to lay her eggs.
  6. I sent Dr. Caldwell a PM, asking him to take a look.
  7. It's probably not trapped. That's a pyrosome - a colonial pelagic tunicate - and it feeds on plankton. Many fish take advantage of jellies for shelter & food. See Dave Wrobel's Jellies Zone - http://jellieszone.com/pyrosoma.htm
  8. Hey Roger -- Dr. Roy Caldwell, THE top stomatopod expert, runs the mantis forum at RC. I was hoping he would reply and he did: "The animal is disoriented by the light. Stomatopods don't have gravity receptors and rely on a doral light reflex to tell which way is up. The lights being used to film probably moving as well as bouncing off the sand confusing the Lysiosquillina. The fish have nothing to do with this behavior."
  9. Wild! Someone here at the museum kept a stomatopod. When live food was put into the tank it would dash out of its burrow, grab the food, somersault & dash back. It never did anything like this. I linked to this thread in the mantis shrimp forum on Reefcentral. Hopefully someone there will check this out & have an answer for you.
  10. Snake eels often have cleaner shrimp perching on them. I wonder if the hogfish needed grooming & was hoping there was one in the vicinity.
  11. Short answer is that they are Bundeopsis (or Viatrix) globulifera but see my reply on your other grass anemone post for more info.
  12. You managed to put up one of the few anemones I do know (sorry, Will!) Depending on which taxonomic authority you follow, either the top 4 are Bundeopsis antillensis and the bottom 1 is Bundeopsis globulifera OR they are all B. antillensis. Researchers who believe there are 2 species separate them in part by the size & shape of the vesicles on the column. These vesicles contain symbiotic dinoflagellates that help feed the anemone. In antillensis they are large & round; in globulifera they are smaller & when expanded are convoluted. The grass anemones in your other post are fully expanded B. globulifera. The two have different behavior as well. Antillensis carries most of the algal symbionts in the vesicles & column so it stays contacted during the day which allows the algae to get maximum light. Globulifera has about half in the vesicles & lower column and half in the tentacles & upper column so it will expand during daylight. Both feed at night by catching zooplankton. The only good comparative images I have for them come from this paper: www.biolbull.org/cgi/reprint/186/2/182.pdf Some researchers believe the differences are meaningless - just adaptations to slightly different habitats. The antillensis "form" is typically shallower & receives more light than the globulifera "form". There's another taxonomic twist in that yet other researchers believe that globulifera is distinct enough to be in its own genus so you will find this in some books under the name Viatrix globulifera.
  13. Sorry, cnidarian are really foreign territory to me - don't even want to guess. Will (Acropora) and James are both knowledgeable so hopefully one of them will drop by.
  14. Hi Bud -- This comes from Dave Pawson, holothuroid expert at the Smithsonian: " I'm sorry, I can't put a name on this holothurian with any certainty - it's possibly a youngish specimen of Astichopus multifidus (Sluiter), which is usually brownish and whitish when it's mature, but brownish specimens have been reported. I don't know of any other shallow-water caribbean holothurians from grassy areas that have that furry appearance"
  15. The front end can regenerate the back portion. Whether a middle piece or a posterior piece can regrow the head depends on what kind of worm it is. In polychaetes - the worm group I know best - some cirratulids reproduce by splitting into pieces as small as 2-3 segments and regrowing both ends. Some polychaetes can only regrow the head if the break is within a certain anterior region of the body.
  16. Thanks for sending the files. Unfortunately, the worm has one of the ends broken off & I can't see the other so I've no way to be sure about the genus.
  17. So we're back to the basic answer of "don't know". We know so little about what's in the sea.... It's a tragedy that we seem determined to kill off so much of it.
  18. What a cool looking little beastie. I dont recognize it but will send the images to friends who might. Or maybe someone else here does???
  19. It's a critter but probably not what you thought. It's a snail with the fleshy mantle drawn up over the body so that the shell is completely hidden. If you've got a lot of free time & really want to know what kind you'll need to go to a site like the Poppe's Marine Icongraphy of the Philippines (www.poppe-images.com) or nudipixel.net & go through their mollusc sections. I'd start with the cowries (family Cypraceae). You'll see some outstanding images of live snails & maybe even find the species.
  20. You're right, it's an anemone. Some species have these string-like defensive organs called acontia. When the anemone is touched the acontia are released through the mouth or through pores on the body wall. They are sticky & adhere to whatever contacts them and they carry nematocysts - stinging cells - to drive off the intruder.
  21. No wonder you were confused. The mating pair are a species of Calappa (now if I were a real crab person I'd know which species without having to look it up )
  22. Yes, and genus Eunice. If I ever get my hands on one I'll be able to tell you what species as well.
  23. Handsome indeed! Downright stunning, and I'd love to see pics of the aggregation if you took some. I've read that these groups occur and have looked for more information but haven't found anything definite. Sex is one possible reason, an abundance of food is another, or an unusually successful settlement of larvae (coincident with good food supply & lack of predators). Some studies that shown that O. flexosus is far more tolerant of pollution & low oxygen levels that other species & will accumulate in large numbers in such areas. Scott Geitler documented a similar mass occurence of another hesionid - possibly Ophiodromus - from Bali - http://ladiving.org/phpBB3/viewtopic.php?f...749&start=0
  24. Only 3 minutes? You mean you wasted the rest of the dive on slugs & other junk when you could have been photographing polychaetes? That's almost as bad as photographing whales & sharks! Nice shot though. It's rare to see one of these outside its burrow.
  25. Bud, we have got to raise some money & get you a good invert book! This is a ribbon worm, phylym Nemertea, not a flatworm which is phylum Platyhelminthes. Not sure, but that might be the recently described Micrura rubramaculosa which was named for the red leopard-like coloration. Would you send me a high-res file? If I can spot one particular feature it will let me know that at least the genus is probably right. lharris[at]nhm[dot]org
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