A Crowned Jellyfish at Kahalu'u

    We had a very enjoyable visit with our son Charles and enjoyed several snorkels during which we found some very good fish and critters.  For his Aloha snorkel he chose to go to Kahalu'u.  No surprise that two days after Christmas it was full of of tourists engaged in full contact snorkeling,

Crowned Jellyfish  Cephea cephea,  Kahalu'u Big Island December 2018

flailing at your humble correspondent and inflicting what damage they could upon the remaining coral.

  Our friend and recent visitor, Kathy Yoder, showed us an insert from the information provided by Snorkel Bob, in which that long time booster of fishwatching in Kona encouraged his patrons to stay away from Kahalu'u.  Give this treasure a chance to rest and regenerate, pleads Snorkel Bob.  It is my opinion that the Yoders would have approached the coral in K Bay with due respect.  Frankly, I am so discouraged by the attitude of many of the tourists that I despond of protecting the sites to which they have access.  Kahalu'u is victim number one.  Short of the county closing the bay for a year or two, I can't imagine that any amount of pleading by Bob, myself or anyone else will have much effect.

Note the fimbriated contractile fringe at the base of the hood. (lower right)

   It took Charles and I a while to thread our way through the maddening crowd in the bay.  Once free, we swam almost to the Menehune Breakwater.  Simultaneously, we spotted what appeared to be a white plastic bag and headed for it, both with the intention of scooping it up to be deposited in the appropriate receptacle on shore.  But low and behold, this was no piece of plastic, but the most wonderful jelly: a crowned Jellyfish,Cepea cephea.

   It was rolling over and over in the current, so it took a moment to appreciate the various components of this jellyfish.  Surmounting the hood was a significant convoluted cap.  At the base of the hood there was a fine fringe that contracted rhythmically.  As the animal was obviously out of control, these contractions had no effect on stability or locomotion.  In fact, this fringe was so delicate that it is hard to imagine a situation where it would be effective.   Kids Zone Critter Squad states that this species lives at extreme depth, as deep as 3000 feet during the day, and ascends to near the surface at night, so that contractile fringe must be more effective than it appears.

The crown is separated from the bell by a deep groove.

 At first I thought that it might be a dislodged upside down jellyfish.  As it happens, this species and the upside down jelly are in the same order, Rhizostomeae.  Jellies of this order do not have tentacles, and what I took for tentacles were actually oral arms, which serve as multiple port for ingesting tiny prey. The crown jellyfish is divided into two components held together by a central trunk.   
The lower component was the solid bell and below that part projected several stubby oral arms, some of which appeared to have been damaged.  Another site, Whatsthatfish, did a good job of elucidating the separation of the crown or umbrella and the lower hood.

   Floating with the current at the same speed, we watched and photographed the crown jellyfish, meandering passively through the multitude of tourists in the process.  Finally, over by the rescue shelter we ended our float.  At this point we were with a group of young Japanese tourists and some fish as well.  A threadfin butterfly took a taste of the jellyfish, but only one nibble.  Perhaps it needed some wasabi.

While we watched, a threadfin took a nibble of the crowned jelly

   Charles, having watched me take so many shots, remarked that I must have some great pictures.  I responded that translucent animals are difficult to photograph, so we would have to see. We have done some small tricks with contrast and red green coloring to enhance these pictures and allow you to see the animal for what it is.

    One final justification...the picture in John Hoover's excellent critter book was taken, amazingly, in this very bay, presumably before the year 2000.  And his picture is no better than any of these.  Translucent animals are difficult to photograph.

   In addition to telling us about the daily migration from deep to shallow, Kids' Zone Critter Squad revealed another tidbit: this species is eaten as a delicacy in Japan.  No mention of wasabi.  Domo arigato. 

 Dragon Wrasse  Kahalu'u  December 2018. This was Charles' Aloha Fish.

    Neither in Hoover nor in any article I found on the internet were those two black spicules mentioned, which figure prominently in at least one picture.  They certainly seemed intrinsic to the animal.


    Following the encounter with the crowned jelly, we saw a large convex crab and a large brown dragon wrasse.  The crab was in the shade and didn't photograph worth a hoot, but the dragon wrasse and the TG 5 connected for a beautiful shot.  I hope you enjoy this look at one of our more unusual fish.

    We had a great time snorkeling with Chuck.  I hope you enjoyed coming along for the ride.

jeff