The leaf scorpionfish is very good at going unnoticed. Not only does it look like a piece of water-logged plant material (which is not uncommon on coastal coral reefs), it also sways back and forth to enhance its camouflage. They make fascinating aquarium residents, but do  remember the spines are venomous.

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.

There are several species in the family Apistidae (which are closely related to scoripnfishes) and one of these species is available to aquarists on rare occasions - this is the longfin or bearded waspfish (Apistus carinatus) (Bloch & Schneider, 1801). This fish ranges from the east coast of Africa and the Red Sea east to the Indo-Malayan Region, north to Japan and south to Queensland. As mentioned above, it is closely related to the scorpionfishes - in fact, not long ago the family was thought to be a subfamily of the Scorpaenidae. While it is commonly called a waspfish, do not confuse it with those of like-name from the family Tetrarogidae.

Bristletooth Filefish - Anemone Terminator!

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).

HARLEQUIN SHRIMPS: Beautiful but Barbarous!

"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 dinner. 

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 sessile invertebrates. 
In this post we will examine these triggerfishes and look at the calculated risk of keeping some of the less suitable species with your invertebrates.


 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. Michael.

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.


  • Select the species you keep carefully – not all species deal with stress in the same way.
  • Feed your fish a nutritious diet.
  • Select tankmates carefully to help avoid aggression problems.
  • Provide lots of behavioral substrate (places to hide).   
  • Maintain optimal environmental conditions (e.g., water quality).
  • Reduce the likelihood of sudden changes in environmental conditions.
  • Capturing, moving or handling your fish should be done as infrequently as possible. 


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 duties. 

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! 

© Scott W. Michael - Reef Tectonics


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.

GOIN TUBING! Keeping Tube Worms (Families Sabellidae and Serpulidae)

 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 worms.