RSS Reef Nuggets 5: Pseudanthias and notes regarding feeding and husbandry

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  1. MASA Admin

    MASA Admin Moderator

    8 May 2007
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    In Reef Nuggets 4 we recounted Macropharyngodon and our personal experience with maintaining a harem using M. vivienae as an example. Today’s installation will aim at covering a topic that’s widely discussed, and on a subject that is ubiquitous and iconic in both the reefs of the ocean as well as our homes. Pseudanthias is high on the list of aquarium favourites and staples, with an impressive repertoire of species that range from fairly affordable shallow water members, to deepwater jewels that command a premium. The genus, as liquid as its form and variability, sees the same inconsistencies with regards to the husbandry requirements of individual species. Not all Pseudanthias are the same, but with exception of a handful of species, a general guideline can be established.

    [​IMG]Pseudanthias aurulentus, a beautiful but pricey member of the “lori complex” that occasionally shows up from the Central Pacific island chains.

    I think as with every article describing a particular set of fish, it’s always best to start from the beginning. That is, what are Anthias? Anthias are an extension of the family Serranidae, which houses mainly large predatory groupers. The familiar fairy type fish we’re accustomed to seeing are nestled within Anthiinae, a subfamily of mostly planktonic feeding smaller sized fish. Anthiinae contains roughly 17 or so genera, and by and large the most populous and popular genus within this subfamily is Pseudanthias.

    Pseudanthias has a rich history dating back to the 1800’s, where many of the species were once placed in the (now only Atlantic and Mediterranean) genus Anthias. Long story short, the smaller more colourful “Anthias” were decidedly different enough to warrant placement in a new genus, Pseudanthias, which literally means “false-anthias”, with reference to their once original placement in the former genus.

    Today, there are slightly under a hundred species of Pseudanthias, with many currently undescribed which will no doubt add to the growing number. Many of them are deepwater denizens that have managed to escape the clutches of science so far, but with more exploration in the recent years, their days of remaining unknown are numbered.

    [​IMG]Pseudanthias bimarginatus, a Maldivian beauty that is a member of the “parvirostris complex”.

    Ask any amateur or professional diver and they will tell you that even a school of the most mundane Pseudanthias squamipinnis is a real treasure and a sight to behold. Who wouldn’t like seeing big schools of Pseudanthias or Luzonichthys swarming in a writhing mass of colour above coral? I know I do, and if you don’t, then something’s probably not right.

    Not everything is rainbows and butterflies in the life of a Pseudanthias however. Pseudanthias are some of the best known reef fish to display protogynous hermaphroditism, a phenomenon whereby females are capable of sex changing into males depending on social cues. Our earlier article on hermaphroditism covers this pretty thoroughly, and would be a good starting point should you find yourself unfamiliar with this terminology.

    What this means is that unlike egalitarian schools, Pseudanthias lead a very competitive life with a complex social and hierarchical standing. A look at a classic shoal of P. tuka for example, may reveal hundreds of individuals, where juveniles and females vastly outnumber the males.  The females may outnumber males by a ratio of about 1 : 8, or more, depending on the species and the geographical area of existence. Males are the most dominant individuals within the shoal, and will make high speed U-turns coupled with heightened coloration to demonstrate their prowess, as well as to suppress their females, and defend their territory. Territories of males are directly influenced by the density of females, and can vary.

    [​IMG]A terminal phased alpha male Pseudanthias aurulentus in display. Here the originally red and white fish has transformed into a bright pink, as it chases away offending intruders.

    Under the direct dominance of the males are the numerous females and juveniles, and even within this class, a hierarchy is established and maintained. Females are aggressive towards smaller conspecifics, and those smaller conspecifics are in turn aggressive towards smaller juveniles. A cast system of dominance is seen from the largest to the smallest, and this is displayed by chasing, fin nipping and fin flaring.

    In typical protogynous hermaphroditic fashion, when the male dies, the next most dominant and largest female in line takes its place. That former female will in turn be replaced by the next most dominant one, and so on and so forth. In the wild, this is acceptable and not detrimental because of the relatively huge territory of a particular coral reef, and the sheer number of individuals. Aggression is spread out amongst many fish and over a large area.

    Pseudanthias species typically fall within a few categories. Shallow water species, deepwater species, species that prefer high flow, and species that prefer slower moving waters. Some species overlap in the categories, such as Pseudanthias ventralis. P. ventralis is a deepwater species that prefers living in slower moving water. Pseudanthias dispar is shallow in its distribution, and prefers swimming above coral heads with faster moving currents.

    [​IMG]Pseudanthias rubrizonatus. Here a beautiful male sporting luxurious colours and fin extensions, a trait that females lack.

    Whatever the preference of depth and habitat, all Pseudanthias are planktivorous fish that hover in the water column to pick floating zooplankton and other small morsels. They are also sexually dichromatic and dimorphic, with males often sporting more luxurious coloration and trailing filamentous extensions on their fins.

    Now that the basic foundation for Pseudanthias is set, we can begin exploring appropriate ways to maintain them in a reef aquarium setting. For me, I feel the three most important factors to consider are tank mates and how many individuals you should keep, feeding and flow. Feeding and flow are two very important factors that are intertwined and very related. We’ll discuss more about this later.

    Tank mates + how many Pseudanthias?

    Recreating a group of Pseudanthias in your aquarium is very tricky. Although it looks peaceful and composed in the wild, we’ve mentioned above that a very tumultuous pecking order exists within the shoal and on the metaphorical shoulders of each individual. Because of the small confines of an aquarium, and the fact that it’s not going to house a couple of hundred individuals, the aggression is not likely to get diffused.

    [​IMG]Pseudanthias bartlettorum. Here a male displays his dominance over a female by intensifying his coloration and erecting his dorsal fin.

    Imagine this. A group of “X” number of Pseudanthias lives in your aquarium. The male suppresses and picks on the females, which in turn picks on the smaller females, which in turn picks on smaller juveniles. The smallest fish at the receiving end is stacked, and receives too much unwanted attention from every individual above the cast. More often than not, these are the ones that will go into hiding, refuse to eat, and slowly pine away.

    There are however, ways to combat this. You’ve seen videos of home aquariums with beautiful shoals of anthias, or public aquariums that look just like the ocean. Species selection, group composition, group size, aquarium size as well as feeding are all factors that can help recreate this scene in your own reef.

    [​IMG]Pseudanthias flavoguttatus is a gorgeous species, but not the easiest to maintain.

    Some species are generally less belligerent than others, and these would make for better shoaling species. Pseudanthias lori and its complex members, i.e, P. aurulentus, P. flavoguttatus etc are generally less bellicose and tend to stay closer together in an aquarium. P. dispar and P. smithvanizi are also good choices. Knowing the temperament of individual species will help greatly in accomplishing your intended outcome. However, a few of these such as P. smithvanizi and P. flavoguttatus are not easy to maintain, and would require additional research and patience should you try.

    Not every anthias does best in a group. Some of the more pugnacious and bigger members like P. fasciatus or P. luzonensis do better alone, and they have no qualms with that. Maintaining a harem of them would require aquariums way larger than most homes can fit.

    Group composition is another important factor one must consider. Like in the wild, a skewed ratio of females/juveniles and males should be maintained. Keeping an all male group would result in incessant fighting and numerous casualties. In general, one male for every four to six females/juveniles is ideal, or if you’re in the mood to watch your fish develop, then an all female/juvenile group is possible. In time, they will sort out the dominance and the most aggressive one will change into a functioning male.

    The size of your anthias group is also just as important as its composition. Crowding your tank with many females or juveniles may help to spread the aggression of the male, and is a technique used in many freshwater aquarium keepers maintaining cichlids. The drawback to this is that for smaller aquariums, too many anthias would mean less space for other fish. It is also important to note that if too great a disparity exists between the sexes, and the male is unable to control every female, then there is a possibility that a female may morph into a male, which may cause problems.

    Generally speaking for an average sized aquarium, anywhere between six to nine individuals is ok, especially if they’re smaller more petite sized species.

    [​IMG]Pseudanthias dispar. A common, fairly cheap and beautiful species. Here a terminal male with a bright orange saddle and a deep red dorsal fin.

    Aquarium size is another major factor to consider. Large aquariums provide more space for smaller more subordinate members to flee away from aggression. It goes without saying that a confined space packed with aggressive conspecifics make for a less than ideal situation.

    Feeding is also just as important, and in this scenario it acts as an aggression suppressor. We will go more on feeding proper later on. Feeding can help to ease aggression, as fish tend to become more antagonistic to one another when hungry. Frequent feeding also allows for the weaker members to get their fill, while keeping the larger members more preoccupied. In general Pseudanthias require heavy feedings, because of their high energy lifestyle. Small frequent feedings three to four times a day is optimal.

    It is not impossible to maintain a thriving tank filled with Pseudanthias. The video above (watch in 1080p HD) of an aquarium in Bangkok shows a tank theming with numerous Pseudanthias of mixed species, living and feeding in harmony. Recreating this takes patience and a lot of planning, but when done right, it makes for an incredible display.

    Lastly for this first factor, tank mates should be taken into consideration. Pseudanthias are often shy when first introduced, and so any large daunting fish is an obvious no go. To ease their transition and to get them feeding, numerous smaller dither fish should be kept.

    This is a proven point and one which i’ve been discussing with another friend of mine for years. Both of us maintain reef tanks, with the same species of Pseudanthias, but mine always begin eating first and transition onto prepared pellets and flakes much sooner. Why? In comparison, an aquarium with higher activity from smaller fish such as chromis, wrasses, gobies and other similar fish will elicit a better response during feeding time, drawing the shyer Pseudanthias out. They very often need such dither fishes to “learn” from, and usually a week is enough to get them trying out new food that enter the water column.

    Remember, Pseudanthias are quite social and active and in a tank with very little movement and activity, they fail to thrive. That is however, not true for all species. More solitary and deepwater Pseudanthias do prefer the peaceful side of life, but in general, most aquarium species are more fond of the latter.

    [​IMG]One of the most ubiquitous species in both the trade and the wild, Pseudanthias squamipinnis.


    Perhaps the heartbreaking crux of maintaining this genus lies in the feeding. Pseudanthias are very often not easy to feed, or are simply not fed enough. Maintaining these fish in captivity requires a lot of work, and initial heavy feedings. Feeding is influenced by a couple of things, but a few important factors to consider are tank mates, suitability of foods, frequency, and flow.

    We’ve discussed tank mates already previously in the above section, and how having dither fish can help in eliciting a feeding response. This might seem like a really trivial thing but trust me, a Pseudanthias in a lifeless tank versus one in a bustling community reef will exhibit a world of difference. I’ve experienced this first hand numerous times. They like company, they like activity.

    Mixing up your Pseudanthias is also a good way to entice a feeding response. In the wild, multi-species crossovers are not uncommon, and more often than not, many different Pseudanthias overlap in their territories to feed above the water column. In my tank I am maintaining Pseudanthias flavicauda and Pseudanthias cf. aurulentus, two sympatric species in the Coral Sea. Although they don’t usually mix during the day, they often feed together during feeding time.

    Suitability of food is another important factor for consideration. It’s pointless to feed nori to a hungry Pseudanthias, or large chunks of pelleted foods to let’s say Pseudanthias randalli. Being small planktivorous fish, they are adept and built to pick small floating morsels from the water column, and that is what you should aim for.

    [​IMG]Pseudanthias parvirostris, a species that houses two similar members in its complex. One of which is pictured far above.

    Flow is a highly important factor that is correlated to feeding, but we will touch on this more later on. Regarding foods, small meaty morsels such as mysid or brine shrimp make for excellent starters. If your Pseudanthias is particularly picky, then live brine shrimp, artemia or cyclopeeze will usually do the trick. A healthy Pseudanthias in good condition will find it difficult to resist at least the three listed food options.

    [​IMG]A microplane with a frozen shrimp.

    One particular food option that I personally have a lot of success with is grated seafood. This might come as a shock to some, in regards to its simplicity. Over the years of maintaing reef aquariums, I have kept numerous Pseudanthias species but not once have I ever dabbled in selcon, or garlic or other fancy additives. Using a simple kitchen microplane (it’s best to have one dedicated for your aquarium) to grate fine shavings of frozen shrimp or squid is an excellent way to entice a reluctant Pseudanthias.

    [​IMG]A microplane will produce very fine shavings of seafood.

    Freezing the shrimp or squid before grating will make it much easier. Nobody said keeping Pseudanthias would be good for your water. Needless to say, adequate skimming and husbandry is needed to maintain such heavy and potent feedings. Turning off the return pumps and letting your shrimp snow circulate around the tank would help greatly, at least for the first few days, in ensuring your Pseudanthias are getting enough to eat.

    [​IMG]Small pellets are a good start in helping your Pseudanthias transition from frozen to dry food. Here a coin for comparison.

    Once your Pseudanthias are feeding well on frozen food, getting them onto dry prepared foods is the next challenge. This often takes time, but a good transition food would be smaller sized pellets such as the one above, mixed in with the usual frozen fare. If your aquarium is full of smaller dither fish that are already accustomed to eating pellets, it is possible that your Pseudanthias will pick up this habit sooner.

    As mentioned before, small frequent feedings is better than one large feeding. Pseudanthias are highly active fish, and spend a large amount of their time swimming, often against currents, and displaying. They don’t gorge themselves, and prefer to pick floating foods passively. As such, feedings of three to four times a day would be best. If they are eating something high in energy content like pellets or flakes, then two times a day should be ok, but nothing less.

    [​IMG]Pseudanthias cf. aurulentus with mouth open showing the “hyperextension” of its jaw.

    The mouth of a Pseudanthias is built in such a way that it can allow for a slight hyperextension of its jaw. The photo above shows this pretty clearly, and you can see why with this mouth structure that they are not suited for bottom feeding or picking foods off of surfaces. They are strictly built for open water feeding, and they use this hyperextension to suck their food.

    This is very evident in the slow motion YouTube video above, of Pseudanthias squamipinnis feeding on a small feeder fish. Watch how the jaw slings forward and extends into a funnel, creating a suction that draws their prey in. This is not noticeable in normal speed, but in a slow motion replay such as this, it becomes very evident.

    This is a great example of its relation to other fishes in the Serranidae family, and many of the larger groupers hunt by this method as well.


    Perhaps the most misunderstood yet important factor for a Pseudanthias is flow. The entire existence of a Pseudanthias is dependent on flow. As we’ve mentioned at the beginning of this blog post, a good portion of Pseudanthias are shallow water fish with high activity. They are most often observed riding currents and swimming against a flow, in a stationary manner.

    As they do this, they pick up floating food morsels while keeping their bodies in relatively stationary position. To understand what we’re talking about here, the video above of my Pseudanthias cf. aurulentus during feeding helps to properly describe this phenomenon (watch in HD).

    Notice how they are actively swimming and moving their bodies, but are not gaining much in terms of distance. This is very clear especially toward the middle of the video. Notice their mouths opening and closing as well, as they pick food off the column while maintaining their position. Unlike other fishes such as wrasses, Pseudanthias seldom actively chase after their food. They might when they get settled down and greedy, but at least for the first few days and weeks, they will exhibit their wild type behaviour, which is this.

    As such, during the initial phase, a tank with no flow will very often not elicit a feeding response, regardless of how much food you introduce. Non-flowing food with dead flow means nothing for a new Pseudanthias, and this is highly important during the transition from wild caught to captivity. This is why flow coupled with feeding is emphasised greatly and harped upon numerous times here.

    [​IMG]Pseudanthias flavicauda, hanging out in an area with slower flow.

    This is of course again, not representative of the entire genus, or family. Please take special note that not all Pseudanthias like flow. As we’ve mentioned before, Pseudanthias ventralis, Pseudanthias hawaiiensis, and various other deeper bodied deep water species can do with a little less flow. Anthias from other genus such as Odontanthias, Tosanoides and Serranocirrhitus are also fans of calmer waters.

    Even for fast moving Pseudanthias, it is important to provide some area of slack for them to rest. I have observed my Pseudanthias flavicauda to occasionally hang around areas of very little flow, sometimes even perched on the rocks or upside down, seemingly “chilling out”.

    [​IMG]Pseudanthias randalli, a common and slightly deeper water species. Here a male with beautiful pelvic fins and colours.

    Flow can make or break your Pseudanthias, and so does feeding. We’ve covered the few main points of what we think is pivotal on keeping this fish, based on our own experience and anecdotal ones. We hope this has been of help, and if you think we’ve missed out anything else that warrants attention, please feel free to leave us a comment at the bottom or on our Facebook page. What are some of your favourite Pseudanthias, and are you currently keeping any with great success? Let us know!
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