Fishes Suitable for the Invertebrate Aquarium
Part II: The Dwarf Basslets (Pseudochromidae)
by J. Charles Delbeek M.Sc.

These fish have only recently been seen in the retail stores of North America 
and new species are still being discovered. They have proven to be hardy,
colourful, disease resistant little fish that are well suited for invertebrate aquariums. 
They are wide spread, occurring throughout the Indo-Pacific area, while numerous
species are endemic to the Red Sea; none have so far been discovered in the
Caribbean. The pseudochromids are closely related to the grouper
family and do indeed resemble their cousins in miniature. At present I am aware of
17 species, Pseudochromis aureus, P. cyanotaenia, P. dutoiti, P. diadema, 
P. flammicauda, P. flavivertex, P. fridmani, P. melanotaenia, P. novaehollandiae,
P. paccagnallae, P. perspicillatus, P. pesi, P. porphyreus, P. purpurascens, P. ruber,
P. sankey and P. springeri. I have seen eight of these species for sale in 
Toronto and four of these could be said to be relatively common in Toronto stores, 
P. cyanotaenia, P. diadema, P. paccagnallae and P. porphyreus.

Dwarf Basslets in the Aquarium
The majority of pseudochromids are small (less than 10 centimeters), shy fish that
must have a plethora of suitable hiding places. The aquarium should contain large 
amounts of dead coral or live rocks in order to make the fish feel secure. The type of 
aquarium needed to keep these species is very important and failure to provide enough 
hiding places for these fish will cause them to become highly stressed and they will suffer 
greatly if not able to find suitable shelter (Achterkamp, 1986; Campbell, 1979). The also 
do not do well in aquariums which contain larger, more active fish such as surgeons or 
angelfish (Debelius, 1986). Once the fish has familiarized itself with all the available 
hiding places it will be more at ease and will be visible the majority of the time 
(Achterkamp, 1986).

It is not a good idea to keep more than one specimen of any species of 
pseudochromid in the same tank since the level of aggression will be too high and
there will be constant fighting until only one is left (Debelius, 1986). The exception,
of course, is if you are able to acquire a guaranteed pair. Pseudochromids should 
be slowly acclimated to artificial light when first introduced to your aquarium and the 
aquarium lights should be dimmed slowly, not suddenly, to prevent panicking them, 
otherwise they might jump out of the tank (Debelius, 1986). The tendency to jump is 
strongest in the first few days after the fish has been introduced to the tank, so make 
sure you have blocked all the exits and overflows during this period. In nature, these
 fish prey upon small planktonic crustaceans and will accept a wide range of prepared 
foods including frozen shrimp and Mysis. Their mouth is surprisingly large compared 
to their body and consequently, they can put away a ather large piece of food.

For full colour photos of the various species I highly recommend Debelius' book 
Fishes for the Invertebrate Aquarium.

The Common Pseudochromids
P. cyanotaenia

This species is commonly imported from the Philippines and Indonesia. The 
colouration is basically light blue with a light brown head and breast, there is also 
a brown horizontal stripe running along the upper half of the body. Shier than most,
 it will tend to remain hidden most of the time (Smit, 1986). The maximum size for
 this species is approximately 6 cm (Smit, 1986).

P. diadema

This species is also commonly imported from the Philippines and Indonesia 
(Smit, 1986). The colouration consists of a predominantly yellow body with a purple 
area along the top of the head. In some specimens there is a white line separating 
the two colours. They can become aggressive towards others of the same species, 
other pseudochromids and other basslets (Debelius, 1986). These fish can also 
become aggressive towards other, smaller fish such as Flame Fish and Mandarins 
to such an extent that they may not be able to get food and will starve to death 
(Achterkamp, 1986). This species can reach a maximum length of 6 cm (Smit, 1986).

P. paccagnallae

This species is commonly imported from the Philippines, Australia and Indonesia. 
They closely resemble the Royal Gramma (Gramma loreto) in colouration, 
however, the purple and yellow colouration does not extend onto the fins to the same 
extent as in G. loreto. There are reportedly two colour forms available. 
One form from Indonesia has a vertical white line separating the purple and yellow 
areas of the body, while the Australian form lacks this stripe (Axelrod and Emmens, 
1971). This species can reach a maximum length of 6 cm (Smit, 1986). A highly 
recommended fish for the beginner, they are extremely hardy and disease resistant. 
However, this species can become extremely aggressive towards others of the same 
species, other pseudochromids and other basslets (Achterkamp, 1986; Debelius, 1986; 
John Burleson, personal communication). It appears that the closer the other fish is in 
colour to P. paccagnallae the greater risk of aggression (Achterkamp, 1986). 
One of our club members lost his Royal Gramma to an overly aggressive 
P. paccagnallae! These fish can also become aggressive towards other, 
smaller fish such as Flame Fish and Mandarins, to such an extent that they may not be 
able to get food and will starve to death (Achterkamp, 1986). Although these fish are 
sensitive to being imported, once they have become acclimatized to your aquarium, 
they can live many years (Mayland, 1981).

P. porphyreus

Commonly imported from the Philippines, this species is probably the most frequently 
encountered in stores. It is basically solid purple in colour with dark blue eyes and clear 
fins. This species has proved to be aggressive towards others of the same species, 
other pseudochromids and other basslets (Debelius, 1986). Just as in
 P. paccagnallae, these fish can also become aggressive towards other, 
smaller fish such as Flame Fish and Mandarins, to such an extent that they may not be 
able to get food and will starve to death (Achterkamp, 1986)

Rare But Seen in Toronto
P. dutoiti (now called P. albabarensis)

A very beautiful fish, it has a more elongated body than other pseudochromids. The base 
colour is a yellowish-orange, while along the upper edge of the body there are a series of 
neon blue stripes extending from the head to the tail. Endemic to the Red Sea, therefore, 
only stores that receive shipments from this area can obtain them.

P. flavivertex

Endemic to the Red Sea as well, this species has a blue body with a yellow stripe running 
along the upper edge of the body from the head to the tail. Peaceful towards other 
pseudochromids and basslets (Debelius, 1986). This species can reach a maximum 
length of 6 cm (Smit, 1986). Another extremely shy species that will not tolerate overly 
active fish in its tank (Smit, 1986). You are most likely to catch glimpses of your pet only as 
it forages for food but they will become bolder with time (Debelius, 1986, Smit, 1986).

P. fridmani

This species closely resembles P. porphyreus in colour, being totally purple, 
however, the purple colour extends onto the fins too. It also has a black line through its eye; 
a peaceful species. It is also a species that is endemic to the Red Sea. This species can 
reach a maximum length of 7 cm (Smit, 1986).

P. novaehollandiae

Little literature is available on this species but the colouration is basically grayish with a 
bright orange head region. There is also a blue arch under each eye. The body has a series 
of light vertical lines and the tail has orange trim. A large species, the specimen I saw was at 
least 15 cm. Currently available only from Australia according to Debelius (1986).

Some Notes on the Other Species
P. aureus

A completely yellow species from the Indo-Pacific (Debelius, 1986).

P. flammicauda

An Australian species (but may be available from other areas) that has soft colours. The head
and tail are bright orange, and the body is a bluish-grey (Debelius, 1986).

P. purpurascens

A very colourful Australian species, it has bright red body and fins with numerous thin, wavy
vertical lines running through its body (Debelius, 1986).

P. ruber

A wine-red species found in the Indo-Pacific (Debelius, 1986).

P. sankey

Another species endemic to the Red Sea, It's body colouration consists of broad 
horizontal black and white stripes (Debelius, 1986).

P. springeri

This species is found also only in the Red Sea. It's body is dark black and it has electric 
blue stripes running from the tip of the head to the back of the head (Debelius, 1986)

References
Achterkamp, A. 1986. Bewust kiezen een serie aquariumtips/5. Het Zee-Aquarium Vol. 36
No. 11:212 217.

Axelrod, H.R. and Emmens C. 1971. Exotic Marine Fishes. TFH Publ. Jersey City, NJ.

Campbell, D.B. 1979. Groupers and their allies: Part III. FAMA Vol. 2, No. 11:39 45,
71 72.

Debelius, H. 1986. Fishes for the Invertebrate Aquarium. Meinders and Elstermann,
Osnabruck.

Mayland, H.J. 1981. Koraalvissen and lagere dieren: Van het tropische rif nar het aquarium.
Thieme and Cie, Zutphen. (Dutch)

Smit, G. 1986. Marine aquariums. FAMA Vol. 9, No. 7:28 31.