Caribbean Compass Yachting Magazine - March 2022

GET TO KNOW YOUR CARIBBEAN MARINE LIFE
Many Blennies to Discover
by Darelle Snyman
Blennies, like their bottom-dwelling goby counterparts (see last month’s Compass),
can easily be overlooked if you are not specifically searching for them. These tiny fish
are definitely in the running for the cutest underwater creature award. But how do
you know you are looking at a blenny and not a goby? Luckily there are some telltale
signs that distinguish the two groups from one another. The fleshy, single or multibranched
projections called cirri that adorn the heads and often snouts of blennies are
a clear indicator that you are dealing with a blenny. The laidback blennies appear to
lounge when perching; gobies in contrast are more stiff and straight in posture. A
closer look will be needed to see that the dorsal fins of blennies are entire and not in
two parts like those of gobies. Like the gobies, blennies also come in an assortment of
shapes, sizes and color variations, making their identification down to species level
quite a daunting task. The easiest approach is probably to become familiar with the
features that set each blenny family apart. That will narrow the field. From there you
can focus on the characteristics that set each genus within a particular family apart.
Or, you can just enjoy the fact that you know you are looking at a blenny and
appreciate its cuteness.
The Spinyhead Blenny
The cutest blennies by far are the tube dwellers. How can you resist those goggleeyed
little faces peeking out at you? The goggle-eyed look is the result of them being
able to see in two directions at the same time.
The tube blennies belong to the family Chaenopsidae and they tend to take up
residence in unoccupied worm and mollusks tubes as well as sponge holes. When you
find one of these bug-eyed faces staring back at you, it might in all likelihood belong
to the Spinyhead Blenny (Acanthemblemaria spinosa). Being only about two inches
long, they are not easy to spot peeking out from their lairs with their distinctive
yellow-green goggle eyes. The snouts and jaws of Spinyhead Blennies are often white
and the compact cirri on their heads give them a crewcut appearance. They are easily
confused with the very similar looking Secretary Blenny (Acanthemblemaria maria).
The somewhat larger Secretary Blenny, however, has a very distinctive orange patch
of short spines over the back of the head.
The Sailfin Blenny
An impressive tube blenny that I would love to catch in the act of displaying its
elaborate dorsal fin is the aptly named Sailfin Blenny (Emblemaria pandionis). The
male Sailfin Blenny is known for moving its large dorsal fin up and down several times
prior to retreating into its hole. Studies have shown that 1,100 of these “flagging”
episodes can occur per day. It is believed that this display is related to courtship and
used as a territorial signal. This display allows you to spot them from a distance, but
they disappear very quickly if approached too closely.
Like most blennies they can also be found propped up by their long ventral fins,
staying partially hidden in their holes. They will only leave the safety of their home for
short periods of time. Sailfin Blennies live in loose colonies. Unlike the males, the
females seem to have no fixed home. A successful courtship will result in the male
staying in the same hole, guarding a clutch of eggs.
The Arrow Blenny
The most unusual looking member of the Chaenopsid clan is probably the Arrow
Blenny (Lucayablennius zingaro). With its slender body and long pointed snout and
jaw, this little blenny looks more like a pipefish.
Arrow Blennies are among the few blennies that do not perch but rather drift with
bended tail to prey on small fish. They tend to ignore divers but will retreat into holes
or empty worm tubes when threatened.
The Redlip Blenny
A blenny with attitude and fun to observe as it sits perched on its ventral fins, ready
to defend its portion of reef real estate, is the Redlip Blenny (Ophioblennius macclurei).
It is a common resident of shallow reef areas and rocky shores. This reddish blenny
can be identified by its blunt head and prominent red lips. It is not shy and quite the
charismatic character to photograph.
Redlip Blennies belong to the family Blenniidae, commonly known as the combtooth
blennies. The term combtooth relates to the single row of comb-like teeth lining their
jaws. Combtooth blennies lack scales, have long dorsal fins and include some of the
largest blennies. Redlip Blennies, for example, can attain lengths of 4.8 inches (12.2
centimeters), which is fairly large considering most of their blenny relatives rarely
exceed three inches.
These territorial critters have no qualms about chasing intruders away and both the
male and female will defend home patches that average about five square feet each.
When not sidetracked by an intruder, much of their day is spend munching on
filamentous algae and detritus within their small territories.
The Saddled Blenny
Blennies belonging to the family Labrisomidae generally have pointed snouts, small
mouths, and, in many, a tall fore-dorsal fin. They are commonly referred to as the
scaly blennies because they bear tiny, difficult-to-see scales. A scaly blenny widely
distributed in the Caribbean is the Saddled Blenny (Malacoctenus triangulatus).
Saddled Blennies are more distinctly patterned, bearing four to five, dark, inverted
triangular bars along their upper body. The males have clear fins while those of the
females are densely spotted.
They like to hang out in crevices in sheltered areas of coral reefs and rocky shores.
These crustacean-eating little fish are highly territorial, and the male Saddled Blenny
is a busy critter, defending its small territory while courting passing females. A female
enticed by the male’s darting movements will follow him to a crevice where she
attaches her adhesive eggs to the substrate. It is then the male’s duty to care for the
eggs and protect them. This is an important task as the eggs are a sought-after food
item of the Bluehead Wrasse (Thalassoma bifasciatum). The clever male Saddled
Blenny will often join forces with a male Beaugregory Damselfish (Stegastes
leucostictus) to co-defend a territory. The larger Beaugregory is a more effective
Bluehead Wrasse deterrent than the smaller blenny.
The Diamond Blenny
A really beautiful Labrisomid blenny often found near giant anemones is the
Diamond Blenny (Malacoctenus boehlkei). It is characterized by pale, diamond-shaped
markings scattered across its lower body. This sharp-snouted blenny has a yellow
head and a conspicuous eye-like spot ringed in yellow on its fore-dorsal fin. It seeks
refuge among the tentacles of the anemone when threatened, unharmed by its
stinging cells. Like many of its kin you will often see it darting about on the reef
bottom between bouts of resting on its pelvic fins. This little carnivore feeds on a
variety of small, bottom-dwelling invertebrates.
—Continued on next page
How can you resist those goggle-eyed little faces peeking out at you?
Arrow Blennies drift with bended tail to prey on small fish.
The Redlip Blenny is fun to observe as it sits perched on its ventral fins.
MARCH 2022 CARIBBEAN COMPASS PAGE 29