TEXT BY HIROYUKI TANAKA

SCOTT MICHAEL

This Pseudochromis paccagnellae was imported from Indonesia. It is one of the most colorful species in the world and makes a good choice for the reef aquarium.

Nymphs of the Sea: The dottybacks
— Pseudochromis paccagnellae
and its allies

When one thinks of the dottybacks (family Pseudochromidae), one might be reminded of the groupers (family Serranidae), which they resemble in appearance and behavior. Dottybacks are primarily small, very beautiful fishes. They do not bother sessile invertebrates and are therefore suitable for reef tanks. In fact, they have been popular reef tank fishes for some time now, particularly in Europe.

In many species, males differ from females in coloration, which has led to them being confused as separate species. About 70 species are now classified in the genus Pseudochromis. The late Roger Lubbock discovered and described many species in the Red Sea, Indian Ocean and southwestern Pacific. His series of descriptions were made in the mid 1970s and early ’80s, but these endeavors were cut short by his sudden and unexpected death in a traffic accident in Brazil in 1981.

A present, Anthony C. Gill, from England, is studying the Pseudochrominae exclusively. Gill has described several new species of Pseudochromis to date, and will soon describe five new species from Indonesia (Gill, personal communication). He will also be publishing a monograph of Pseudochrominae through the J. L. B. Smith Institution of Ichthyology in the near future.

In this article I will examine the members of Pseudochromis paccagnellae complex, an especially exquisite group of dottybacks. These include some very popular species in the aquarium trade, while some have been described only recently. All the members have only pink or a combination of pink and yellow coloration. This complex is comprised of six species, one of which is undescribed (see Table I).

TABLE I Pseudochromis paccagnellae Complex
Species	Describer/Year	Distribution	Maximum Size
P. aurifrons	Lubbock 1980	New Guinea (Irian Jaya and southwestern Papua, New Guinea	6 centimeters (2 1/3 inches)
P. diadema	Lubbock and Randall 1978	the Philippines, Malay Penninsula and northern Borneo	5.5 centimeters (a little over 2 inches)
P. ephippiatus	Gill, Pyle and Earle 1996	southern Papua, New Guinea	5 centimeters (2 inches)
P. paccagnellae	Axelrod 1973	Indonesia, Timor Sea, Papua, New Guinea and the Solomon Islands	7 centimeters (2 3/4 inches)
P. porphyreus	Lubbock and Goldman 1974	the Ryukyus, Taiwan, the Philippines, eastern Indonesia, Belau, the Solomon Islands, Vanuatu, Fiji and Samoa	5.5 centimeters (a little over 2 inches)
P. sp. (undescribed)		the Great Barrier Reef and New Caledonia	7 centimeters (2 3/4 inches)

Pseudochromis paccagnellae was described on the basis of seven specimens from Indonesia (Axelrod1973). Since then, the species has been recorded from various localities, including eastern Indonesia, northern Australia, Papua New, Guinea, the Solomon Islands and New Caledonia. Moreover, this species has proven to be very common throughout its range.

It is a mystery that such a beauty was not discovered until relatively recently. Axelrod (1973) suggested the possibility that Great Barrier Reef specimens might represent a distinct species, based on the absence of a white bar between the pink and yellow colors. However, Gill (1993) noted that the specimens with white bars occur throughout the range of the species. In the future, Gill (personal communication) will divide the P. paccagnellae we commonly see in the trade into two separate species: P. paccagnellae from Indonesia, the northwest shelf of Australia, Papua, New Guinea and the Solomon Islands, and an undescribed species from the Great Barrier Reef and New Caledonia. The latter species differs from P. paccagnellae in having smaller (and more numerous) scales.

RUDIE KUITER

Note the dotted pattern on this male Cypho species. The photo was taken north of Sulawesi.

The two species are very similar in form and coloration and are suitable for reef tanks. However, they can be aggressive toward other fishes. Because they may kill less aggressive tankmates, it is best to keep them with more aggressive species. Keep a close eye on them when they are first introduced into a new tank. They may be harrassed by more aggressive fishes, and will stay in a corner of the tank, not eat and eventually starve to death. Make sure to provide them with ample hiding places.

Like other pseudochromids, these fishes are carnivorous and will accept pieces of raw fish, as well as commercial foods available in most aquarium stores. Keep the tank covered, as this species is prone to jumping, particularly when it is chased by other fishes. I once experienced this with a Paccagnellae’s dottyback I kept in a 180-liter (48-gallon) tank with some angel- and damselfish species. I awoke one morning to find the dottyback’s dried, dead body on the floor.

Another time I saw a 4-centimeter long (1 1/2 inch) Paccagnellae’s dottyback cleaning an 8-centimeter (3 inch) long two-spined angelfish (Centropyge bispinosa) in a fish-only tank. This was indeed exciting for me. The angelfish spread its fins and did not move while it was being cleaned. The cleaning behavior was similar to that observed in cleaner wrasses (Labroides dimidiatus). I have observed this behavior between the dottyback and the angel only once, and have never seen the angelfish request a cleaning since.

GLENN BARRALL

Pseudochromis aurifrons is one of the rarest species in the paccagnellae complex and this individual is thought to be the third individual known to science. Note the amount of yellow around the face, the head and the back. The belly appears to be whitish. The second known specimen has yellow only around the lips.

There have been reports of cleaning behavior in some other dottybacks. P.aldabraensis and P. springeri have often been observed cleaning other fishes. Both of these species possess blue stripes on their sides, a feature that is common among cleaner fishes (Michael 1995).

P. porphyreus and P. diadema are not as aggressive as P. paccagnellae and will often succumb to the attacks of more aggressive species. These species frequently lose their vivid colors when kept over a long period of time, particularly when they are housed with other fishes. I once saw an almost white P. diadema at a public aquarium. It was kept with an assortment of 50 larger and smaller species in a large tank that was furnished with only rocks and decorative corals. Debelius (1986) reported that one P. paccagnellae kept its pink coloration for over three years in an invertebrate tank and other reefkeepers have had similar experiences.

Llong-term bright coloration is only possible when these species are kept in the right environment (i.e., strong lighting and a varied diet). Of course, these fishes can exhibit bright coloration in community aquaria for short periods of time.

SCOTT MICHAEL

The lips of this Pseudochromis diadema are totally pink and appears not to be a sexual difference.

Pseudochromis paccagnellae can frequently be aggressive. Debelius (1986) kept one such individual in a tank with a more aggressive juvenile Pomacanthus annularis and several cleaner shrimps (Lysmata amboinensis). According to him, the P. paccagnellae bit off the eyes of three L. amboinensis immediately after he removed the annularis. While it is best not to keep more than one individual of the genus in the same tank, there are some exceptions — several specimens of the King Solomon fish or the Fridmani (P. fridmani) can be kept together in the same aquarium.

There are no significant differences in color between the sexes in this complex. All of the species have been described since 1973.

The golden browed, or goldcrown, dottyback (P.aurifrons)

Only one specimen of P. aurifrons was known, until two underwater photos of this species appeared in magazines in the United States in the 1990s. The species was originally described from a single specimen from Port Moresby, Papua, New Guinea, by Roger Lubbock (1980). P. paccagnellae was not found at the same locality, although Lubbock reported it elsewhere in Papua, New Guinea.

The type specimen was bluish gray with a yellow crown. The specific name refers to the yellow coloration. Barrall and Gill (1997) reported that it also occurs in Biak, Irian Jaya, where it tends to be pink and yellow, with the yellow coloration on the head, and dorsal and ventral parts of the body varying somewhat in different individuals. Although Pseudochromis paccagnellae has not been recorded from the same area, according to Barrall and Gill, P. porphyreus does occur.

SCOTT MICHAEL

This photo shows the dorsal view of of an undescribed Pseudochromis species. This species will soon be formally described by Anthony Gill. The photo was taken in the Great Barrier Reef of Australia.

Pseudochromis aurifrons lives at depths of 21 to 48 meters (68 to over 150 feet). As yet it is not seen in the aquarium trade, but there are collectors working in the Biak area to change this situation.

The saddled dottyback (P.ephippiatus)

This species was discovered by Richard L. Pyle and John Earle, two ichthyologists from Hawaii, in 1995. They collected one at a depth of 30 meters (about 100 feet) and another at 48 meters, in Papua, New Guinea. At that time, they observed four specimens between 30 and 50 meters (100 to 160 feet). P. paccagnellae was also seen and was abundant between 2 to 70 meters (6 to 230 feet) (Gill, Pyle and Earle 1996). The specific name was derived from the yellow saddle on the fish’s back.

The diadem dottyback (P. diadema)

This is a common species that exhibits variations in color. The amount of yellow may vary among individuals and some have pink lips. There are no color differences between the sexes and there is no great change in color with growth. Some have a narrow white stripe dividing the two colors (Debelius1986), which is considered a variation. The environment and/or heredity may greatly influence color. They are commonly sold at pet shops at low prices and the pink coloration may gradually fade initially, although the yellow remains the same.

The species has not been recorded from Taiwan or the Ryukyu Islands. The scientific name was derived from its purplish-pink “diadem” (headband), and it is sometimes referred to as the purple-capped dottyback. There is a very similar fish in Sipadan that has a broader pink area on the lips, cheeks and anterior half of body, but again, it is thought to be another color variant of the species.

RUDIE KUITER

The black spot on the dorsal fin of this Cypho purpurascens is prominent in this individual. It was photographed in Papua, New Guinea.

The magenta dottyback (P. porphyreus)

This species is also widely distributed in the western Pacific, especially in the northern areas. It ranges south to Vanuatu and east to Samoa. It is easily distinguishable by its color pattern.

The depth range for the magenta dottyback is 6 to 65 meters (20 to 210 feet)(Myers,1989). Although it is somewhat similar to the Red Sea endemic P. fridmani, it can be readily differentiated. P. porphyreus can be kept in a group as long as there is ample space in the tank. This is a popular species among reefkeepers, but do not forget that it can be pugnacious toward less-aggressive fishes. Because it is the cheapest and most readily available species at marine aquarium shops, it is also quite popular.

Identification

Are there any other identifying characteristics for these fishes besides color? For taxonomic purposes, the fish are examined after they have been soaked in formalin, so it is hard to distinguish their colors (Barrall and Gill1997). While color patterns are important in identifying a species there are some meristic (measurement) differences in these species as well (see Table II).

TABLE II Merristic characteristics used to identify members of the Pseudochromis pacagnellae Complex
Species	Dorsal Fin Rays	Anal Fin Rays	Lateral Line Scales	Gill Rakers	Scales in Lateral Line
P. aurifrons	22	12	24	6 + 5 (= 21)	36
P. diadema	21 to 22	11 to 12	19 to 24	7 + 13 to 15 (= 18 to 21)	31
P. ephippiatus	20 to 22	12	21 to 24	7 + 14 to 15 (= 20 to 22)	35
P. paccagnellae	21 to 22	11 to 13	17 to 27	8 + 14 to 17 (= 19 to 24)	33
P. porphyreus	21 to 22	10 to 12	19 to 26	8 + 13 to 15 (= 21 to 23)	33
P. sp.	21 to 22	12	22 to 28	8 + 14 to 16 (= 22 to 24)	36 (usually 38 to 42) (Gill, personal communication)
Note that almost all of these characters are identical in the various species. The noteworthy exception is P. sp., which has higher numbers of scales in lateral series.

Epilogue

For the most part, male and female Pseudochromis species exhibit different coloration: the females are darker or black. Because they do not feed on corals, are smaller and quite attractive, this group of fishes is popular with reefkeepers. They can be easily kept if you pay attention to their requirements. One U.S. hatchery has even been able to successfully spawn and rear some of the Pseudochromis species (Scott Michael,personal communication). Some pseudochromid species mimic other fishes. For example, Pseudochromis paranox mimics the midnight angelfish (Centropyge nox). Apparently this predatory Pseudochromis gains an advantage by mimicking an omnivorous grazer, because it is able to get close to prey fishes. In Oman, P. leucorhynchus and Oman ypsilon closely resemble each other in coloration (Gill and Mee1993). In this case it is not known which species is doing the mimicking. And, as I mentioned previously, some blue-striped dottybacks behave much like the cleaner wrasses.

Pseudochrominae is comprised of 10 genera, including some undescribed. The total number of the species is now around 80, and the genus Pseudochromis is the largest. However, name Pseudochromis is given only provisionally (Gill et al.1996) — it may be split into smaller genera in the future.

The genus Pseudochromis includes some 50 to 60 species (Gill,et al.,1996). New species are continuing to be discovered and the distribution range of known species are also changing. P. striatus has recently been recorded from Iriomote and Kumejima Islands in Japan (Shibukawa and Iwata 1997, Kawamoto, personal communication) and its Japanese name has been applied.

SCOTT MICHAEL

The longfin dottyback (Pseudochromis polynemus) is a beautiful species that has been more readily available to aquarists in the last few months. Note the markings on the pelvic fins, which can be red or yellowish-orange.

I would also like to mention the new genus Cypho. It is comprised of two species. C.purpurascens ranges from southern Indonesia, the Great Barrier Reef, New Guinea, Vanuatu, Fiji and Tonga. It is called the oblique-lined dottyback. It was previously referred to as Pseudochromis purpurascens or P. mccullochi (or maccullochi).

The other Cypho species is undescribed and is distributed from northern Indonesia, the Philippines and Taiwan (Gill1993). It was reported from the Yaeyama Islands by a Japanese diver. Its popular name is the checkered dottyback. This fish is very similar in appearance to C. purpurascens, but close observation reveals a subtle differences: the lined or dotted pattern. Some C. purpurascens also have a dark eye spot (ocellus) on the dorsal fin.

I am looking forward to seeing Gill’s publication on this attractive group of fishes, but financial support is needed. He will have to pay aroun &7500 (U.S.) for publication (Gill, personal communication). He would appreciate any help on this problem. The late Roger Lubbock must be eagerly awaiting this monograph in heaven.

Acknowledgements — I should express my greatest gratitude to Dr. Anthony C.Gill, who has kindly revised my only superficial writings and he added very important informations, some of which have not been published yet. Also many thanks to Dr. Gerald R. Allen, Mr. Glenn Barrall, Mr. Tsuyoshi Kawamoto, Mr. Rudie H. Kuiter, Mr. Scott W. Michael, and Dr. John Randall who have kindly provided me so many photographs and precious informations as well. This article has never been accomplished without their professional supports.

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