The author was fortunate enough to come across a pair of mating Raja epaulette
sharks on a night dive.
The epaulette sharks gained world-wide fame in 2006 when they were described as “walking sharks” by a group of ichthyologists sea rching for new species in West Papua (Irian Jaya). The media picked up on these “new walking sharks” not realizing these sharks had been familiar to those that are shark-inclined for centuries! That said, their habit of “walking” is especially interesting. They crawl along the sea floor on their muscular pectoral and pelvic fins, preferring this form of locomotion to swimming (they will swim if they are trying to cover a greater distance more rapidly). Not only do their specialized fins make them ideally adapted to a benthic lifestyle, their serpentine-like body type means they are better-suited for crawling and slinking between and within reef fissures, coral branches and the limited confines of the home aquarium.
There are a number of marine fishes that are renowned for their aggressive tendencies. One of these is the Sohal surgeonfish (Acanthurus sohal). This is truly a “bad boy” of the reef! The Sohal shown in this video (which was named Kevin by one of the patients at this rehab facility) was kept in a 700-gallon aquarium. It regularly dashed around your hand as you attempted to clean the aquarium, but it never brought its caudal peduncle spine to bear. However, it would nip your hand and forearms! Not only did it let the Reef Tectonics technician know that it was boss, it had a particular disdain for the magnet we used to clean the aquarium - as you will see if you watch this video. (Note: that this video was taken after the surgeonfish had calmed down a little bit - his initial attacks were even more savage!).
A beautiful pink leaf scorpionfish interacts with a light colored
individual off Ambon, Indonesia. The pink fish, which I would suggest
is a male, flops from side-to-side in front of what may be a female
There are three things that are important in the life of a fish (or any
other organism). One: to acquire something to eat. Two: to avoid being
eaten. And three (if you succeed in getting enough nutrients and steer
clear of your hungry neighbors): to reproduce. One thing that can help a
fish to achieve the first two objectives is to look like something that
it is not, like an algae encrusted rock or a toxic sponge. This
antipredation/feeding adaptation is referred to as camouflage or
crypsis. Crypsis can take one of two forms: either a fish can match its
surroundings so it goes totally undetected (i.e., eucrypsis) or it can
take on the appearance and actions of something inedible (i.e.,
masquerade). One of the best examples of eucrypsis in the coral reef
community is the leaf scorpionfish (Taenianotus triacanthus).
With its laterally compressed body and high dorsal fin it resembles a
leaf or the frond of a macroalgae. It enhances its mimicry of plant
material by rocking back and forth or by swaying from side-to-side.
The longfin waspfish is spectacular species that is not easy to keep
in the home aquarium. At night it emerges from the sand and cruises just
over the bottom hunting.
There are many of aquarists that are always in search of the bizarre.
There are a number of scorpionfishes that fall into this category and
some of these show-up in the aquarium stores from time to time. These
fishes are like fine art - they don't move around much but they are
beautiful to behold as they remain in repose on the bottom of the tank
or on the rock-work.
The glass anemone destroyer - the bristle-tail filefish (Acreichthys tomentosus)
A number of years ago, I shared information about the bristle-tail filefish (Acreichthys tomentosus)
in a magazine article. I found that in Europe, that many aquarists
included this species in their reef aquarium fish community to take care
of both glass anemones (Aiptasia spp.) and the dreaded Majano anemones (Anemonia cf. majano). The European reef-keepers swore up and down that they did not harm other cnidarians in the tank. When originally introducing A. tomentosus
as a potential reef aquarium inhabitant I did suggest that there was
some data that they may pick at xeniid corals, leather corals and
large-polyped stony corals. Since that time, I have kept a dozen of
these fish in my own and customer aquariums and have found that they are
not as trust-worthy as I had hoped. Yes, they love to munch on those
annoying little anemones (at least some individuals anyway), but they
also might nip at the tentacles of more desirable sea anemones (e.g., Entacmaea quadricolor), the tips of gorgonian branches and the fleshy polyps of a variety of large-polyped stony corals (e.g., Acanthastrea, Turbinaria, Lobophyllia, Trachyphyllia).
"Oh what pretty tube-feet you have!" A pair of harlequin shrimp on a
rubble patch off the coast of Sulawesi are having a Linkia seastar for
The beautiful harlequin shrimps have often been considered as a
difficult crustacean to care for. In actuality, they are very easy to
keep as long as you meet their specialized nutritional need – that is,
provide them with sea star flesh! The harlequin shrimp are members of
the family Hymenoceridae and the genus Hymenocera. Some
crustacean experts think there is only one species in this genus, while
others split the Indo-west Pacific and central and eastern Pacific forms
(the former is recognized as Hymenocera elegans while the latter would be H. picta). Both “species” of harlequin shrimp are white to cream overall with large purplish blotches with blue margins (H. elegans) or maroon with yellow margins (H. picta).
The redtooth or niger triggerfish (Odonus niger) is a handsome
fish that can be kept in a reef aquarium. Of all the potentially
reef-safe triggerfishes, this is one with a more dubious reputation. It
will eat ornamental crustaceans and as it grows larger, it may attack
and even kill fish tankmates.
Triggerfishes have long had a bad reputation for being voracious
predators and aquarium bullies. Many of the triggers are some of the
most polyphagous of all fishes, eating everything
from algae, sponges and corals, to all kinds of crustaceans and even
smaller fishes. So the idea of adding one of these beasts to a reef
aquarium, packed with succulent invertebrates, seems a bit daft! While
it is true, the majority of triggerfishes are not appropriate
invertebrate aquarium neighbors, there is a relatively small group of
triggers that have more specialized diets that can be housed with
In this post we will examine these triggerfishes and look at the
calculated risk of keeping some of the less suitable species with your
A male ribbon eel with the characteristic flared nostrils and barbel-like filaments on the lower jaw.
The ribbon eel (Rhinomuraena quaesita) is typically considered
one of the most beautiful morays found on coral reefs. Not only does it
exhibit bold colors, the elongate body with high dorsal and anal fins,
give the impression of a flowing streamer, especially as this eel
undulates over the substrate. While many aquarists are attracted to the
idea of keeping one of these remarkable morays in their home aquarium,
most steer clear after doing a little research in fish books or on the
internet. Why? Because they are considered one of the most difficult
morays to keep feed. In this installment, we will look at some general
and specific observations on the ribbon eel.
The large terminal phase Creole wrasse is a sight to behold!
The family Labridae, known commonly as wrasses, is comprised of a
plethora of beautiful, aquarium-suited species that have become more and
more popular over the decades. The cradle of diversity for these fishes
is the Indo-West Pacific. But there are also a number of species that
can be found swimming about Atlantic coral reefs and some of these are
readily available to aquarists. One member of the Atlantic labrid guild
that is often overlooked by fish-keepers is the Creole wrasse (Clepticus parrae).
While not a great choice for those with smaller aquariums, it is a
fascinating, and attractive selection for larger reef aquariums. So
let's take a closer look at the Creole wrasse.
Skunk cleaner shrimp inspects the mouth of a complying anthias. Photo by Scott W.
We aquarists have long suggested that cleaner shrimps will remove cysts from fishes infected with Cryptocaryon irritans and
may also ingest other parasites (e.g., trematode flatworms). Well, it
turns out that science supports our anecdotal observations. Let's take a
look at the scientific evidence. The first study of interest was
conducted by Williams and Williams (1998) - they documented that
Pederson's anemone shrimp (Periclimenes pedersoni) feeds on the
larvae of parasitic isopods. Even more exciting was a study done by
Becker and Grutter (2004). They analyzed cleaner shrimp gut contents as
well as conducted some aquarium studies. They found that wild cleaner
shrimps in the genus Urocaridella and Ancylomenes (formerly Periclimenes) holthuisi (known commonly as Holthuis' anemone shrimp) fed on parasitic crustaceans (e.g., isopods, copepods) and monogenean flatworms (Benedenia sp.). They also demonstrated that captive A. holthuisi
reduced the parasitic load (in this case flatworms) by 74 % on captive
surgeonfish. In the most recent study, Militz and Hutson (2015)
documented that captive -held skunk cleaner shrimp (Lysmata amboinensis) will reduce infestations of a trematode in the genus Neobenedenia in groups of lyretail anthias (Pseudanthias squamipinnis).
The shrimp reduced the infection success by the trematodes by half
compared to controls that were not housed with shrimp. These beneficial
crustaceans were found to eat both the flatworm's eggs and the larvae.
The key to keeping your marine fishes healthy, like this Limbaugh's angelfish (Holacanthus limbaughi), is to keep stress at a minimum. Photo by Scott W. Michael
Reducing stress to our fish is indeed one of the biggest challenges we
face as marine fish keepers. Your marine fishes are exposed to stress
from the moment the diver begins the process of trying to catch them.
The fish is then transported, in an unfamiliar environment (e.g., a
bucket or live well), to tanks on shore. In some cases the fish are
handled carefully and provided with proper care, but not always. In most
collection stations where the fish are caught and at wholesalers here
in the states, the fish are held in bare tanks. This makes it easier for
staff or customers to observe the fish. But, think about this for a
moment. You have a fish that was living in a coral labyrinth, where
hiding places abound, that is now in a little Plexiglas box without any
shelter. Even if other environmental parameters (e.g., water quality)
are optimal, this fish is more than likely going to experience some
degree of stress.
A pair of yellow shrimpgobies (Cryptocentrus cinctus) and
an undescribed species of snapping shrimp on a sandy slope in the Raja
Ampats. The gobies keep watch as the shrimp performs its maintenance
In the shrimpgoby-snapping (pistol) shrimp relationship both members
benefit (mutualistic). The shrimp’s burrow provides a sanctuary for the
otherwise vulnerable goby. In exchange, the gobies act as
"seeing-eye" fish for their relatively poor-sighted crustacean
partners (note: some crustacean experts have suggested that these shrimp
actually see quite well, even so their visual acuity is not as good as that of
the goby). As the shrimp keeps house or feeds just outside of the burrow, the
goby will sit near the burrow’s entrance and “stand guard” (it will also feed
and interact with conspecifics at this time as well). The crustacean moves
freely in and out of its refuge, but when it leaves the burrow it keeps in
contact with the vigilant goby. It does this by placing one of its antennae on
the fish. When a predatory fish approaches, the goby will rapidly flick its
tail, warning the shrimp of impending danger. If the goby flicks its tail once
the shrimp may not respond, but if the goby executes a series of flicks the
shrimp will retreat. If the predator comes within a critical distance, the goby
will also dart into its hiding place.
We at Reef Tectonics love shrimpgobies and their snapping
shrimp partners and would love to set-up this fantastic symbiotic
relationship in your aquarium!
There are a number of snails that are employed to help turn the upper
layers of the sand bed and to scavenge on food items that come to rest
on the aquarium bottom. Most of these are small, relatively
bland-looking snails. For example, the members of the genus Nassarius
are probably the most often utilized in this role. There common name,
mud snails, attests not only to their habitat preferences but also their
not so sexy appearance! But there is a genus of gastropods that is not
only effective at clean-up duties, but also are very attractive. These
are the snails in the genus Babylonia (family Babyloniidae), two or more of which show-up in the aquarium trade on occasion (including Babylonia zeylanica and B. formosae).
These snails sport butterscotch colored blotches on a white to
yellowish-cream background. They reach an appreciable size for a snail
(around 2.5 inches) and are harvested for human consumption in some
parts of Asia.
The beautiful Coco Worm (Protula magnifica) is a difficult animal to keep long-term.
Tube worms are beautiful, fascinating members of the class Polychaeta.
They are also the most popular polychaetes available to aquarists.
Larger species are intentionally purchased and added to the reef tank
because of their elegant form and or their lovely colors, while smaller
species often come in with live corals (i.e., living on the rocky bases
that the corals are growing on). Unfortunately, the larger species often
don’t fare as well as their much-malign brethren, the bristle or fire
I had a fish jumping incident happen recently that was difficult to
comprehend. A Reef Tectonics client had a longnose hawkfish (Oxycirrhites typus)
that had been in his aquarium for over a year. It was a “happy” fish
that seemed to live a copacetic life with its tankmates. While working
on the tank, I broke a small portion of the glass top (this resulted in
an opening about four by three inches in the front portion of the
cover). Before I could replace the top, the hawkfish was found dried up
on the office floor – it had jumped out. I was perplexed as to why the
fish jumped and how the fish was able to detect the hole in the top that
had not been there for its first year in the aquarium?
Acoel flatworms can reach plague proportions in the home aquarium. The photos shows Waminoa flatworms on a bubble coral.
The acoel flatworms are some of the most primitive animals on the
planet. They actually lack a body cavity and a gut. Most of the
flatworms we encounter in the aquarium trade are innocuous, causing no
harm to corals. The acoels that are most often encountered living on
mushroom anemones, soft corals and large-polyped stony corals are
reported to graze on minute crustaceans, algae and detritus that adheres
to the mucus of these cnidarians. When in small numbers, they do not
appear to harm their host, but severe infestations can interfere with
the photosynthetic activity of the zooxanthellae-hosting corals they
Cephalopholis igarashiensis (a.k.a., the garish hind) is an
amazing grouper that is poorly known to aquarists and scientists alike
because of its proclivity for deep reef habitats - it occurs at depths
in excess of 250 feet and is most often found in excess of 400 feet. As a
result, it is not likely to show-up in your local aquarium store
anytime soon. This individual was selling for $ 6,000 at House of Fins
in Greenwich Connecticut (sorry, this photo was taken a couple of years
ago and the fish has since been sold). Virtually nothing is known about
its biology. It has been reported from southern Japan, Taiwan, Guam,
the south China Sea, American Samoa, Tahiti and Fiji. It reaches a
maximum length of around 17 inches.
Reef fishes, like this dwarf
hawkfish, comes into the tank with behavioral baggage that can cause
problems in a captive fish community. Photo by Scott W. Michael.
One of the biggest problems encountered by marine fish keepers is
aggression. It can cause disease and death, especially in newly
introduced fishes. So how do we deal with it in our aquariums? There are
several phenomenon related to animal ethology that we need to “unpack”
before we try and solve our problems with “tank rage.”
A gorgeous Australian harlequin tuskfish. This species is displaying towards a tankmate.
Reef Tectonic's clients love the harlequin tusk (Choerodon fasciatus)! And
why wouldn’t they? They are indeed one of the most beautiful fish
inhabiting the reefs of the western Pacific. The tuskfishes are members
of the wrasse family Labridae and is the only member of the genus Choerodon that is found in the aquarium trade with any regularity.Let's take a closer look at the biology and husbandry requirements of this fish.
Welcome to the Reef Tectonics Blog! We hope that this blog will
enable us to communicate with our valued clients as well as anyone that
loves aquatic organisms and aquariums! We welcome your feedback on the
subject matter discussed on the blog and suggestions on future
contributions. You can also visit our website (www.reeftectonics.com) and our facebook page! Happy fish-keeping!
Reef Tectonics Aquarium Maintenance and Design - Lincoln, Omaha, Des Moines, Kansas City