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Leslie

Critter Expert
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Posts posted by Leslie


  1. :oops: :oops: :oops:

    Now that Brook has sent me a higher resolution file (thanks, Brook!) & I've re-examined the image I'm embarrassed to admit that the worm isn't a bobbit as I said earlier but belongs to the family Onuphidae, genus Diopatra. These guys are called decorator or farmer worms because they attach bits of live algae as well as sticks, shells, etc., to the outside of their tubes. The extra bits add camoflague and attract small animals which the Diopatras may eat, plus the algae itself often serves as food for the worms. There's a nice photo of one showing the spiral gills at http://www2.uol.com.br/cienciahoje/chdia/galeri29.htm (click on the photo for an enlargement)

    Leslie


  2. Hi Dave --

    You and Brook have different species, maybe even different genera. The color patterns are very different, and note the area at the base of the long head appendages.... in your critter there's just one thin ring while in Brook's there's multiple rings. The tubes are different too, and that's another species-level character.

     

    Matt -- Hey neightbor! USC, huh...you must be pretty happy with the Trojans right now. Walk over anytime you want a private tour or help with critters.

    :D

    Leslie


  3. Bobbit is just a common name for the big eunicids seen by divers. 99% of all eunicids are much smaller as adults. The one Brook photographed could be either an adult of a small species or a juvenile of one of the large ones. For a really big one (although preserved) check out the article at

    http://www.nhm.org/research/annelida/learn_more.html

    For head shots of live small ones go to http://www.nhm.org/guana/bvi-invt/bvi-surv...rv/worm-g04.htm

    Cheers, Leslie


  4. Nice picture! As James said, it's in the family Eunicidae, most likely in the genus Eunice. I'd have to have the specimen & check out the bristles, arrangement of gills (the fluffy-looking bits inside the tube), the jaws, & some other characters to really know the genus & species.

    I'd love to have a higher resolution file if you wouldn't mind. I'm curious as to how many different species get lumped under the common name "bobbit worm".

    Thanks, Leslie


  5. There actually are recorded cases of pearlfish seeking refuge in fishermen & swimmers but some fish are even worse. A particularly nasty little freshwater fish lives in South America; it follows urine streams back into people's urethers then erects the dorsal spines to keep from being dislodged. And for those of you heading off to PNG you might want to stay out of streams & rivers according to the news item below.... or at least invest in some cast-iron swim trunks!

    Leslie

     

     

    Two die in fish dismemberment

    PORT MORESBY

    Friday 6 July 2001

     

    Two Papua New Guinea fishermen have bled to death after having their

    penises

    bitten off by pirahna-like river fish. The fish, which zero in on urine

    streams in the water, have struck terror among villagers along the Sepik

    River, in north-western PNG. Authorities believe the killer fish is an

    introduced member of the South American pacu family and a relative of the

    piranha. In both of last month's fatalities, the fish demonstrated a trait

    of the piranha by

    following a trail of urine in the water, swimming to its source and then

    biting it off with razor-sharp teeth. Some believe the killer may be a

    food-source fish introduced from Brazil in 1994 by the United Nations Food

    and Agricultural Organisation and the PNG National Fisheries Authority.

    However, marine biologist and aquaculturist Ian Middleton said he believed

    they were a different species, introduced from across the PNG-Indonesia

    border. He believed the fish had started biting humans because of a lack of

    naturally occurring food. "The reason for biting people on their genitals

    is a result of the fish detecting a chemical change in the water, swimming

    up the urine trail and

    biting the genitals." This behavior was well documented in the Amazon, he

    said. The director of the PNG Office of Environment and Conservation, Dr

    Wari Iamo, yesterday expressed "grave concern and dissatisfaction" at the

    way some government agencies and donor organisations had gone about

    importing exotic plant and animal species.


  6. Hi Alex -- Our fish guys, Rick Feeney & Jeff Seigel thought it was a carapid so I checked FishBase. It looks an awful lot like a pearlfish, Carapus bermudensis. Pearlfish are the little guys with the bizarre habit of living inside the body cavity of sea cucumbers. They live inside the cukes during the days & go out to forage during the night. <http://www.fishbase.org/summary/SpeciesSummary.cfm?id=3128>

    Cheers, leslie


  7. Try a tight crop, leaving out the diver in the background but leaving in the tall sponges, and with the fish slightly off center. The fish will become the focal point. the nice thing about Photoshop is that you can experiment with different crops until you get the shot you want.

    Have fun, Leslie


  8. Hi William -- Is the fish or the diver supposed to be the focal point? All the various parts of the images are fine but they don't add up well, at least for me. My eyes keep getting drawn away to the diver despite the fact I'd really prefer to focus on the fish!

    Leslie


  9. Which blue-spotted? Blenniella caudolineata? The facial pattern is different & it has a distinctive head fin that Linda's little guy doesn't seem to have ( at least it doesn't show). Marli's awfully good with fish ids; maybe she can put a name to this. Otherwise Linda's just going to have to go back for some more pics!

    Leslie


  10. Hi Linda -- I noticed your blenny shot last week & spent some time trying to put a name on it. Failed miserably.... just couldn't match it to anything in my books or on the web. I don't think it's Glyptoparus delicatulus as the head appendages aren't the same, the coloring's diferent, and the mouths are different. Genera like Blenniella or Istiblennius looked better but I ended up leaving it as blenny unidentified. Let's hope a blenny expert will take a look at it! Good luck, Leslie


  11. Hi --

     

    It's appears to be a Nemanthus anemone with all but a few white tentacles withdrawn into its mouth. Both the Gosliner, Behrens & Williams and Colin & Arneson guidebooks have pictures of Nemanthus annamensis. This has white, cream, orange, or red markings. On the web you'll find some information at

    http://www.edge-of-reef.com/anemoni/ESANem...nnamensisen.htm

    The edge-of-reef site says the color markings are brown. Your black-patterned critter might be undescribed or just a color variant. All sources say that it's unknown whether the anemone settles on dead gorgonians or if it settles on & kills live ones.

    Cheers, Leslie


  12. Thanks, Don. Nice of you not to mention the incorrect spelling. It should be Ceratosoma tenue....my cat was on my lap & it's hard to type around her. There are a number of wetpixelians who have impressive knowledge about inverts - Alex, James, Marli, Art, DaveH, etc., and they know a lot more about the living critters. I just know stuff from books.

     

    Unfortunately our marine hall dates back to about 1976 with just a few small updates after that. It''s dominated by local habitat dioramas & fish. On the other hand, you're welcome to come down for a behind-the scenes tour if you're interested.

     

    Cheers, Leslie


  13. Occurrence of parasites like Saculina vary with each species & each population. In an area with lots of boxer crabs in fairly close proximity the incidence of infected crabs could get pretty high for a while. Eventually the number of boxers will drop because they're not reproducing. What I find fascinating about this kind of parasite is that they basically take over the brains & reproductive systems of their hosts. Other types of parasites alter the behavior of their hosts, for example causing a fish that normally swims along an estuary bottom to swim near the water surface where it can be eaten by a bird, allowing the parasite to continue onto the next stage of its life cycle. If this kind of stuff interests you read "Parasite Rex" by Carl Zimmer. Well written & easy to read, "Parasite Rex" is full of this kind of great stuff. In fact, it mentions that some scientists think that evolution was/is driven by the need to stay ahead of parasites - even the switch from asexual to sexual reproduction!


  14. Hi Alex -- It's an endoparasitic barnacle belonging to the order Rhizocephala. Saculina is the best known genus in the group. Their bodies are divided into 2 parts - the interna which absords nutrients and the externa which is the reproductive part. Once established in the host's body they inhibit molting & basically "castrate" the crab. What looks like the egg mass of the crab is the externa, the egg mass of the barnacle. The crab treats the barnacle egg mass like it's own, aerating it and using its legs to liberate the juveniles when they hatch. Pretty cool, huh?

    Leslie


  15. Finally got them - what a great set of images! Obviously that cuttle didn't deserve to pass its genes on if it could be distracted by a camera instead of paying attention to the real threat. It's a darwinian world out there. And Cavie, how do you know Paul's not getting a gold star in the Pearly Gates book for being nice to lizardfish?

    Leslie


  16. The first one. The pygmy is beautifully focused with good views of the face in both images. The arrangement of the soft coral in the background of the 1st makes the pygmy the center of attention. In the 2nd the 2 coral branches pointing off to the top right draws your attention away from the seahorse. Cropping the 2nd would help tighten the image.

    Leslie


  17. I've never read any stories about this guy's venom, just that it can be deadly. Once I was working aboard ship doing trawls when a guy got stung by the local scorpionfish. His hand become extremely swollen & painful but he was quite macho & kept on sorting fish. A colleague was on another cruise when a woman sat on a scorpionfish (don't ask, I don't know details). She went into shock & had to be airlifted off the ship. The Indo-Pacific scorpions are supposed to be much worse than ours.

     

    Keeping busy working on images. Haven't seen the sun in days but I'm getting a lovely computer tan.

    L

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