Category: Marine Invertebrates

Bioluminescence Night Kayaking

tumblr_lb8aepifVZ1qda2n5o1_1280Last night we had an amazing light show during our first of several bioluminescence night paddles in Elkhorn Slough. Before the water began to sparkle with light producing dinoflagellates, sea otters and harbor seals popped up near by. Marine mammal interactions are quite different at night. Many species produced a “cold light”, a chemical reaction that emits sparks of light. Bioluminescence may serve as a warning, a lure, communication or mate selection. As our paddles glided through the water, light exploded below us, light dripping from the paddles.

We’ve added 2 more Bioluminescence night paddles, Sept 12th and 13th. We hope teachers will bring their students as well booking a school field trip during September and early October. Details Photos from internet, my water camera is in repair!



Each year during our Caribbean programs in Belize and the British Virgin Islands,  our group is invariably drawn to the Caribbean Reef Squid, Sepioteuthis sepioidea. Even seasoned snorkelers become overwhelmed by the explosion of colorful activity found on a coral reef. Suspended in blue water, an erie feeling that something is watching you creeps into your consciousness. A quick glance around reveals a squadron of reef squid. Swim away and they follow. Move towards them and they quickly change color, a deep red if near the reef or pale if over sand, masters of camouflage.



They may even create false eyes on their posterior end as seen here. The eyes will instantaneously vanish once the threat of a predator is gone. Quite incredible.


The  picture  below reveals an unusual white blotch across the dorsal side. I have watched reef squid for decades and have rarely seen such coloration. It appears as though we may have interrupted the amorous intentions of a courting male.



Reef squid not only expand and contract the chromatophore cells embedded in their skin to conceal themselves, but do so as part of their mating ritual. Males may flash an impressive zebra pattern to the female who is revealing a blotchy saddle indicating her sexual receptivity. Mate selection is a serious business to a female reef squid. She will die soon after depositing her fertilized eggs in a safe corner of the ocean floor. Like most cephalopods, the life of the Caribbean Reef Squid is relatively short. They are thought to live for one year, mate and die.

Join Blue Water Ventures on a naturalist-led adventure to the reefs, rain forest,  kelp beds and beyond!


Imagine a jellied filled sac, a simple life form that saw the Dinosaurs come and go, flourishing on earth for over 300 million years. You have no brain nor heart or even a proper anus. You have just consumed the soft juicy tissues of a California mussel, dislodged from the grasps of its stringy cementing agent by a powerful wave. The calcareous mussel shell pops out of your mouth that serves as both the beginning and end of your digestive tract.

Sea anemones, though a mere bundle of jelly, are formidable predators. They are armored with 1000’s of stinging cells known as nematocyst that capture their prey. The aggregating anemone pictured here can produce sexually through the dispersal of egg and sperm or asexually by cloning. Essentially, they pull themselves apart creating a genetic clone over and over again until they blanket their rocky condo. Specialized warrior polyps on the edges of the colony inflate with powerful nematocyst cells that will attack neighboring colonies. In some cases a neutral zone between colonies will be established where each colony is spared the lethal reach of the other.

Fantastic discovery today while kayaking in the Elkhorn Slough. We found an  enormous  California brown sea hare, Aplysia californica, a type of marine  slug in the phylum mollusca. Enjoying a hermaphroditic life style, this fascinating guy or girl as the case may be emitted a mildly toxic purple dye as I scooped it up and placed  it on  my spray skirt.OLYMPUS DIGITAL CAMERA



Using their raspy tongue or file like structure known as a radula, sea hares scrap into their algae diet which later  aids in the pigmentation of their ink. Why do sea hares as well as their relatives, octopus and squid emit a dye? Perhaps the cloud of purple confuses or startles a predator or serves as a screen or decoy. Possessing some of the largest nerve cells in the animal kingdom, sea hares have been used in studies on memory and learning.

OLYMPUS DIGITAL CAMERAMy group of kayakers though a bit startled, politely watched as I rolled myself face first into the sand while still cradling the sea hare in my arms. Covered with purple dye from head to toe, I do think they realized what a special find we had!

Join the naturalist of Blue Water Ventures as we explore Central California, Baja, Belize, Tonga and beyond!




Have you ever wandered a beach and found seashells with a small holed drilled into it? There are several marine snails that use their radula, a file like tongue to bore into their prey. Among them is the moon snail. The tiny single holes in the bivalves pictured here were made by a predatory snail, perhaps a moon snail or oyster drill. The photo reveals a shell on the right which is riddled with multiple tiny holes. This is from the dissolving activity of a boring sponge in the genus, Cilonia. These sponges use a dissolving chemical to bore into calcium rich species such as snails and corals. Rather than seeking prey, boring sponges are in pursuit of a habitat taking up residence in a calcareous animal….life on a gulf coast beach.


Next time you are kayaking in Elkhorn Slough take a look around the launch area. There is a vast diversity of life clinging to the docks and hiding in the mudflats. The bright orange species is a colonial tunicate. In their larval stage tunicates sport around with a primitive spinal cord which places them into phylum chordata, the same category that humans and all animals with backbones belong to. Our naturalist at  love to share their knowledge of what lives above and below. Be sure to fire those questions our way on your next kayaking tour with us.

During our yearly expedition to the Sea Of  Cortez, we made an incredible discovery. A tiny, barely discernible commensal shrimp was  found living among the tube feet of Bradley’s Sea Star (Mithrodia bradeyi). The sea star shrimp (Periclimenes sorer) was barely visible until we realized it was mimicing the tube feet of the sea star.



The Creature Featured today is the Monterey Stalked Tunicate (Styela montereyensis).  Also known as sea squirts,  the tunicates are  more linked to humans than those octopus with clever thoughts,  crabs with their fancy  jointed appendages or  sea hares with their  joy of sex (mass orgies).   In fact, they belong to a group of  animals known as the Urochordates, a subphylum of  phylum  Chordata, animals with backbones.  In their larval form tunicates have  a primitive spinal cord, stomach and heart .  As  free swimming youngsters,  they sport  an appearance resembling  a  tiny  tadpole or human embryo.  As adults, Styela montereyensis claim a sedentary life attached to a surge channel or the  ocean floor filtering plankton through their dual siphons.  Check out for our next naturalist-led adventure.DSCF36282

Here’s an unusual find, the internal shell structure of a sea butterfly, Corolla spectabilis. As the name implies this pelagic gelatinous snail can swim rapidly through the water as it escapes its predators. To feed, it oozes a muscus snare to capture its planktonic prey. We found this while exploring Greyhound Rock. Winter offers excellent tides that may reveal unusual sea creatures.
To learn more about this interesting species found in Monterey Bay National Marine Sanctuary check out:

While surf fishing today, we were distracted by the tide pools. Leptaasterias hexactis, known also as the Six Rayed or Brooding Sea Star only reaches a size of slightly more than 3 inches. This particular star pictured has lost a leg to an intertidal predator. While many sea stars reproduce by broadcasting their egg and sperm into the water column, these little stars are attentive mothers. Females will stand guard over a mass of yellow eggs and then guard her young stars until they are foraging on their own.Tasty mollusks such as the Lined Chiton are considered a delicacy by these tiny echinoderms. The brooding process may take several months all while the female is fasting.

Learn more on our next extreme tidepooling adventure for families on October 19th, 2013  at