Introduction

The species in the genus Paracheilinus are appropriately called flasher wrasses (or simply flashers), and they are very closely related to fairy wrasses of the genus Cirrhilabrus. Dr. John E. McCosker is the ichthyologist credited for originally naming Paracheilinus as the Flasher Wrasse, and this common name is derived from their grandeur "flashing" behavior observed during courting or mating where the male will make quick, exaggerated lateral moves while intensifying his colors and erecting his fins to attract a mate. The genus is composed of 14 species that are found in the Indo-West Pacific Oceans, from the Red Sea and the Kenyan coast to Samoa, and from southern Japan and the Marshall Islands to the Great Barrier Reef. They have been kept by many aquarists around the world, but the genus was relatively unknown to the hobby until 2002 since many of its members were, unfortunately, misidentified or overlooked by fish collectors. Here I show all the known species and illustrate several recently introduced or newly described members, and I will discuss the differences between similar or related species of the genus.

Paracheilinus Availability in Japan

Species/Named by/Locale	Availability
P. angulatus - (Randall & Lubbock, 1981) - Philippines, Indonesia & Malaysia	Commonly seen in the aquarium trade; inexpensive.
P. attenuatus - (Randall, 1999) - Seychelles & Kenya	Scarce; very expensive; only variation from Kenya.
P. bellae - (Randall, 1988) - Marshalls, Palau & Iriomote	Scarce; very expensive.
P. carpenteri - (Randall & Lubbock, 1981) - West Pacific	Common; inexpensive.
P. cyaneus - (Kuiter & Allen, 1999) - Central Indonesia	Fairly common; not so expensive.
P. filamentosus - (Allen, 1974) - West Pacific	Common; inexpensive.
P. flavianalis - (Kuiter & Allen, 1999) - Indonesia & Western Australia	Common; inexpensive.
P. hemitaeniatus - (Randall & Harmelin-Vivien, 1977) - Madagascar & South Africa	Not available.
P. lineopunctatus - (Randall & Lubbock, 1981) - Philippines & Indonesia	Common; inexpensive.
P. mccoskeri - (Randall & Harmelin-Vivien, 1977) - Indian Ocean	Common; inexpensive; some variations.
P. octotaenia - (Fourmanoir, 1955) - Red Sea	Fairly common; not so expensive.
P. piscilineatus - (Cornic, 1987) - Mauritius	Scarce; extremely expensive.
P. rubricaudalis - (Randall & Allen, 2003) - Fiji & Vanuatu	Rare; very expensive.
P. togeanensis - (Kuiter & Allen, 1999) - Sulawesi, Indonesia	Not available.

Species Discussion

Paracheilinus carpenteri (Carpenter's Flasher Wrasse; Figures 1 & 2 below), reaching up to 8cm in length, is one of the most common members in the trade and is shipped from the Philippines on a regular basis. As can be seen from the photos below the males are gorgeously colored with reddish-orange to yellow on their body and blue lines on their side.

These three species, P. carpenteri (Figures 1 & 2), P. flavianalis (Figures 3 & 4) and P. mccoskeri (Figures 5 & 6), are very similar in appearance and are easily confused with one another (see Table 2 for distinguishing characteristics). Paracheilinus carpenteri has two to four yellow filaments on its dorsal fin. Also, this species often has a black area on its caudal fin and occasionally another on its dorsal fin, while P. flavianalis usually has two or three filaments, but the caudal fin areas sometimes range from one to four and are essentially red. Males of P. mccoskeri have a single yellow filament that does not change color. There is another significant difference in the coloration of the anal fin: in P. carpenteri and P. mccoskeri it is yellow and red on the outer third, while in P. flavianalis the anal fin is entirely yellow, thereby giving it the name Yellow-fin Flasher Wrasse.

Table 2.

Species	Anal Fin	Number of Filaments
P. carpenteri	Red on outer part	2 - 4
P. flavianalis	Entirely yellow	1 - 4
P. mccoskeri	Red on outer part	1

These three species do not co-exist in any range: P. carpenteri is distributed in the western Pacific from southern Japan to the Philippines and Palau, P. flavianalis is found in Indonesia, Bali, Flores and Western Australia, and P. mccoskeri is found only in the Indian Ocean from Kenya's coast to the Andaman Sea. Exceptional and mysterious underwater photographic records of P. carpenteri and P. mccoskeri adult males were made in Bali where P. flavianalis is very common. Very few imports of marine fish from Kenya include P. mccoskeri and P. attenuatus; both are similar-looking but the latter has a tapering caudal fin.

Paracheilinus attenuatus (Figures 7 & 8 below) was regarded as P. mccoskeri until recently (Randall, 1999) and was originally described by a specimen from the Seychelles, although there are no current shipments from this area as far as I know. Dr. John Randall once informed me that he would soon be describing a new species of Paracheilinus from the Seychelles, and then I remembered that Takeshi Aoki of Tokyo had long kept a female from Kenya that eventually changed into a fully-grown male (in 1998). I informed Randall of the Kenyan male and he wished to examine it, so Aoki kindly sent me the specimen to preserve in formalin. Eventually, Randall named it by using several specimens, including Aoki's (Randall, 1999). It is only rarely seen at retailers in Japan, and I unexpectedly and very luckily obtained a female in 2003. The Kenyan males have a slightly different coloration with a blackish area on their caudal fin.

I obtained males of P. cyaneus (the Blue Flasher Wrasse; Figures 9, 11 & 17) for the first time from a Japanese friend/shipper in Bali in 1997, when the species had yet to be named. They were still young (all were 5 - 6 cm in length) but had several long filaments on their dorsal fin. They were sold to me as P. filamentosus but I was astonished to discover that they were actually P. cyaneus after publication of the species from Indonesia and Western Australia in 1999 (Kuiter & Allen). Males of P. cyaneus, however, can be distinguished from P. filamentosus by the many fine dots on their side and also their back is often greenish (Figure 17). Prior to 2004, the species could be seen in stores only on rare occasions, but now it is readily available and some reach a size of nearly 8cm long.

Another common species from northern Indonesia, P. lineopunctatus (the Line-spot Flasher Wrasse; Figures 10 & 12 below), is not a close relative of P. cyaneus, but appears very similar when they are displaying. The latter, however, has a rounded caudal fin.

Paracheilinus rubricaudalis, the Red-tailed Flasher Wrasse (Figures 13 & 14 below), is the newest member imported from Fiji and Vanuatu and was not described until 2003 (Randall & Allen). It is somewhat larger than P. mccoskeri, its close relative, and will reach almost 9 cm in length. They are shipped only from Vanuatu on rare occasions, and remain expensive. The species has a red tail and a broad red zone with a single filament on its dorsal fin. Males have a reddish area on their distal anal fin. The reddish stripes on their sides turn whitish and their body becomes bright yellow while they are displaying. Males from Fiji have a narrow bluish vertical stripe on their caudal fin that is never seen on specimens from Vanuatu.

Figure 17. Males of P. filamentosus (upper) and P. cyaneus (lower).

Paracheilinus angulatus (the Angular Flasher Wrasse; Figure 15 above), P. filamentosus (the Filamented Flasher Wrasse; Figures 16, 17 & 18) and P. octotaenia (the Red Sea Flasher Wrasse; Figure 19) are now available on a regular basis in the trade, but the last one still is somewhat rare due to its distribution from the Red Sea. Paracheilinus angulatus is characterized by sharply pointed dorsal and anal fins with no filament, and also by an emarginate caudal fin. It is regularly available but is never included in shipments from some areas of the Philippines, suggesting either that the species does not inhabit some specific areas within its range or that collectors in the area do not get orders for it or know of it. Paracheilinus angulatus, a rare species, is somewhat similar in appearance to P. togeanensis but is distinguished by its rounded dorsal fin.

Paracheilinus bellae, which I have never seen sold in the trade, is very similar to P. filamentosus with which it co-exists. Paracheilinus bellae has a distinct yellow area on the center of its caudal fin while males of P. filamentosus have five to seven filaments on their dorsal fin and also lines on their side, but are plain between the lines.

Paracheilinus togeanensis is a true rarity; only a few have been sighted in and collected from their natural habitat in Sulawesi, Indonesia. An excellent underwater photo of a pair was shown as P. angulatus on the US FishBase website, but it has been deleted from the website since I pointed out they were actually specimens of P. togeanensis. I had no idea why the picture was not shown in the P. togeanensis section, but soon realized that they do not intend to show it because no one knows who took the photo!

Several popular species are commonly misnamed, including the well-known "Pink Flasher" that is similar to P. carpenteri and other similar looking hybrids as well (e.g., P. flavianalis x P. filamentosus, etc.). Additionally, sometimes I find unusually shaped or colored specimens that are not typical of any valid species. I suspect that these are naturally hybridized specimens, and they often are observed by divers, especially around famous diving sites in Indonesia and the Philippines. These areas are the homes of many Paracheilinus and they often mix in the same localities. In my experience, the hybrid of P. filamentosus x P. flavianalis (Figure 20 below) is the most abundant in the aquarium trade. The hybrids possess elements of both parents that can be readily seen, especially in their caudal-fin's shape and filaments. Also, a careful observation of the dorsal and anal fins' coloration could determine the parent species of the individual, and parental species' distributions may also provide an important hint (Kuiter & Allen 1999).

Paracheilinus hemitaeniatus (the Half-banded Flasher Wrasse) and P. piscilineatus (the Elegant Flasher Wrasse) are restricted to small areas of the western Indian Ocean. Paracheilinus hemitaeniatus is not available in the trade, and P. piscilineatus is extremely rare in the trade; I have never seen one offered for sale. I know that several "undescribed" species remain in the field that are known from various, but small, localities in the Pacific Ocean, including Iriomote (Japan), the Great Barrier Reef (Australia), Palau, Samoa and the Philippines. I hope that these will soon be collected by extensive diving and named by ichthyologists.

Flasher Wrasses in the Aquarium

The flasher wrasses are plankton feeders and are very easy to feed in the captive environment. They feed well on variety of foods including wet or freeze-dried brine shrimp, flake foods, fresh small clams and a variety of other meaty foods. With proper care, they can live long in captivity. Remember, however, that they can be jumpers in non-covered tanks and need many crevices for hiding and also plenty of open space to swim freely. For adult flasher wrasses a tank size of at least 60 x 30 x 30 cm should be sufficient, but juveniles can be kept in smaller aquariums. Unlike some other wrasses that sleep in the sand, they do not need a sand bed as flasher wrasses create a mucus cocoon over their bodies for sleeping. They generally require the same care as the related fairy wrasses. If you are lucky enough to find several individuals of the same species at a retailer, you should choose the largest specimen first and then select other, smaller males or females. Introduce all of them into the tank at the same time or release the younger or smaller specimens first in order to minimize the larger fish from picking on the smaller ones. They can be kept along with other Paracheilinus males and/or females of any species as well as Cirrhilabrus species in the same tank. Of course, you may have a single individual in a tank that can live longer than its tankmates, but if you want to see their flashing behavior, I recommend keeping as many specimens as possible, especially males. They generally do not harm the typical invertebrates kept as display organisms, and they easily adapt to reef systems. Flashers can be kept with smaller angelfishes such as Centropyge, non-aggressive damsels, wrasses of different genera, cardinalfishes, seahorses and pipefishes, butterflyfishes, and other non-aggressive fish. Paracheilinus males may fight, but usually this does not cause any serious damage; although if one continues to hide or retire you may want to remove the weakest or the strongest, and keep it in a separate tank for several weeks.

Acknowledgement:

Many thanks to Takeshi Aoki who provided his male Paracheilinus attenuatus photo that made this article more colorful and accurate.

References:

Kuiter, R.H. 2002. Fairy & Rainbow Wrasses and their Relatives. TMC Publishing. Chorelywood. 208pp.

Kuiter, R. H. & Allen, G. R. 1999. Descriptions of three new wrasses (Teleostoi [sic]: Perciformes: Labridae: *Paracheilinus*) from Indonesia and north-western Australia with evidence of possible hybridisation. Aqua, J. Ichthy. Aquat. Biol. 119-132.

Kuiter, R.H. & Debelius, H. 2006. World Atlas of Marine Aquarium Fishes. TMC-Publishing. 710pp.

Randall, J.E., 1999. Paracheilinus attenuatus, a new labrid fish from the western Indian Ocean, with a redescription of P. piscilineatus. J. South Asian Nat. Hist. 4(1):29-38.

Randall, J.E., & Allen, G. R. 2003. Paracheilinus rubricaudalis, a new species of flasher wrasse (Perciformes: Labridae) from Fiji.. J. Ichthyol. Aquat. Biol. 7(3):103-112.