Into the Labyrinth: A Taste of Licorice (Part 2)

Author: Mark Denaro

The spectacular colors of licorice gouramis continue to attract aquarium hobbyists. Unfortunately, they will seldom display their coloration in a dealer’s tank or upon receipt from an online vendor. This can make species identification difficult—a challenge that is compounded by the fact that most of the licorice gouramis available for purchase are sold as Parosphromenus deissneri, even though very few (if any) actually are.

As such, there are 20 described species and numerous undescribed forms. In this column, I’ll help you try to identify the species most likely to be available in the hobby.

Original Designation

There is a great deal of confusion regarding P. deissneri. Bleeker’s original description was based on a single female specimen from Bangka Island. However, we now know that there are two species found there. They are most easily differentiated by the shape of the caudal fin in males, with one being round and the other spade-shaped. Unfortunately, since the type specimen was female, it is difficult to determine which species was actually P. deissneri and which was not.

Hazy Anatomy

The fish traditionally sold as P. deissneri have always had a round caudal fin. However, Kottelat and Ng later redescribed the species and chose the one with the spade-shaped caudal fin to be designated as P. deissneri. Meanwhile, the species with the round caudal fin was described as P. bintan because it was also found on Bintan Island. Thus, uncertainty regarding the species’ identification has increased. As designations are regularly changed, aquarists have learned to be flexible when it comes to their scientific names.

The Former P. deissneri

Further complicating the situation is that aquarium fish have not historically been collected on either Bangka or Bintan Island. This has changed recently, and fish from these locations are now occasionally available, but it doesn’t change the past. What fish, then, were in the hobby as P. deissneri? By my estimate, it was likely a mix of species that included P. tweediei, P. rubrimontis, and P. alfredi. Of course, some undescribed forms could have been involved as well.

Over 50 Forms

Space constraints will not allow us to include a discussion of the more than 50 known forms that have not yet been scientifically described. We will focus on the described species most likely to be encountered by aquarists. Let’s begin with the “real” P. deissneri before proceeding to other species that may have been misidentified as such, then moving on to those with very different coloration.

P deissneri

P. deissneri, as previously noted, is now considered to be endemic to Bangka Island. Males have a spade-shaped caudal fin. Male coloration consists of a cream to tan base color with two horizontal black stripes, with one running through the eye to the end of the caudal peduncle and the other one just above this. There is a black stripe at the base of the dorsal and anal fins. The unpaired fins feature the typical striped pattern, but in this case the inner blue stripe is a series of spots rather than a solid stripe. The fins are also edged in blue. This species can grow to 2 inches (5 cm), making it the largest of the Parosphromenus group.

P. bintan

P. bintan has a round caudal fin and grows to nearly 1½ inches (4 cm). The male’s body is light brown with three dark gray to black horizontal stripes. These stripes are broader than those in many other species. The first starts at the mouth and runs through the eye, bending above the iris. The second starts on the mouth and runs straight through the iris. Both of these end at the base of the tail. The third stripe starts on the chin and runs along the ventral surface of the fish, ending at the mid-body. It can appear that the line runs the length of the body because part of the anal fin is black as well. The pattern in the unpaired fins is a row of blue spots on a black fin. The spots can be close enough together that they appear to be connected on some individuals. The outer edge of the fins are also blue or blue-white.

P. tweediei

The male body of P. tweediei features three black stripes on a light brown overall color. The unpaired fins have a black band running along the edge, with a red stripe inside that is broken in the dorsal and anal by a blue spot at (or near) the center of the fin. There may also be a blue patch on the anterior end of the anal fin, and in some individuals this can be a large area. The blue on the anal fin is the most variable marking on this species. There is another black stripe on all three fins, which also feature a white edge. Its natural habitat appears to now be limited to the Johor State in western Malaysia following habitat destruction in the rest of its range. P. tweediei grows to 1½ inches (4 cm).

P. rubrimontis

It is my belief that P. rubrimontis was the fish most frequently imported as P. deissneri for as long as I’ve been in the hobby. Unfortunately, it is also becoming increasingly scarce due to habitat destruction. The expansion of oil palm plantations is likely to ultimately result in the decimation of this species in the wild. Its home range is around Red Mountain (which is the meaning of rubrimontis) in the Perak state of Malaysia. Males in breeding condition feature three black stripes on a light brown body. The dorsal portion of the body above the highest black stripe is a darker brown than the lower body. The unpaired fins are black with a white edge. The stripe in the middle of the fins is red. This species can reach close to 1½ inches (4 cm) in length.

P. alfredi

The fin coloration in male P. alfredi is more intricate, making it less likely to be labeled as P. deissneri, though this occasionally happens. Males sport three black lines on a very light-colored body. The dorsal and caudal fins begin with a black line that follows the contour of the fin adjacent to the body. There is a red band on the dorsal (which can be reduced to a series of spots), followed by a layer of light blue-white, then a black band, and finally a thin layer of blue-white at the edge. The anal fin begins with a variable area of dark blue and black followed by a light blue stripe, then a black stripe and a blue-white edge. Some individuals will also have a red stripe in the anal fin. This species grows to 11⁄5 inch (3 cm). It, too, is endangered in its natural range due to habitat destruction and is now limited to the remnants of peat forest swamps in Johor. Next, we move on to species that have probably never been sold as P. deissneri.

P. sumatranus and P. anjunganensis

P. sumatranus and P. anjunganensis are easily recognized by the males’ red fins. Both are available with some regularity in the aquarium trade.

The first is P. sumatranus. This nearly 1½-inch (4-cm) species is found in Jambi on the island of Sumatra. Fins of the males are not solid red, so it is not difficult to differentiate from P. anjunganensis. The fins feature a variable pattern of red and black stripes, sometimes with a white stripe as well. Because it comes from an area that is regularly collected for aquarium species, P. sumatranus is available to hobbyists on at least a recurring basis.

The other red-finned species is P. anjunganensis, sometimes known as the angel licorice gourami, which hails from Kalimantan Barat in Borneo, specifically the area around Anjungan in the region of the Kapuas River. The threat to this species from human activity is high because much of its habitat is being drained for agricultural projects. It can be recognized by the light brown body color of the males, which also features two darker brown horizontal stripes. The dorsal, caudal, anal, and pelvic fins are red with a white edge. P. anjunganensis can reach just under 1½ inches (4 cm) in length.

P. nagyi

P. nagyi is named after the Austrian Peter Nagy, who first brought this nearly 1½-inch (4-cm) species to Europe in 1979. Found on peninsular Malaysia in a number of locations in Pahang state, as well as further north in the state of Terengganu, it has a larger range than some of the other licorice gouramis. This just might be my favorite species in the genus. To my eye, it is a particularly beautiful fish, with males featuring a reddish body color that gets darker as it gets closer to the ventral surface. It has black along the lower part of the body, with this coloration continuing to the anal and pelvic fins. The base of the dorsal and caudal is black as well. This is followed by a blue band in all the unpaired fins, followed by another black band, and then a blue edge. While this coloration is typical, there can be some variation depending on where the fish were collected. If possible, find out where your P. nagyi were collected, and don’t breed them with fish from different locations, as these may, at some point, be described as separate species.

P. parvulus

P. parvulus has a pattern somewhat reminiscent of P. nagyi when in breeding condition, but overall it is more slender and the body coloration is darker. However, the biggest difference is in the fins. The dorsal and anal fins of male P. parvulus are black with some red spots and a white edge. The caudal fin is less colorful and generally appears reddish but fairly clear. Its body is shaped much like that of P. ornaticauda, but the color pattern of mature males is very different. While P. parvulus can reach a length of almost 1½ inches (4 cm), I’ve never seen a specimen that exceeded one inch (2.5 cm). This species is native to Central Kalimantan in Indonesian Borneo.

P. ornaticauda

The ornately finned licorice gourami P. ornaticauda is one of the most desirable species in the genus and has long been sought after by anabantoid aficionados. It is not, however, one of the easier species to maintain and is particularly difficult to spawn. It has been spawned in Europe, generally at a pH of 4.0 or less; the highest pH I’ve seen reported for a spawn has been 4.5.

While every fish in the genus benefits from the addition of leaf litter to the aquarium, P. ornaticauda seems to appreciate this the most. The first time I ever got the species in, I received 50 fish that were placed in a 10-gallon (38-liter) tank with a few Indian almond leaves. The next morning, I immediately checked on the tank, only to be disappointed by not seeing a single fish in it. I thought, “Oh, no, they didn’t like the water so they jumped out!” After inspecting the floor, I still hadn’t found any of them, and none were visible in the neighboring tanks. Because they still had to be somewhere in the tank, the next thing I did was lift the leaf closest to the front, where I found them huddled en masse. There was a group under every leaf. Even after they started venturing out, they would retreat to the shelter of the leaves whenever they were disturbed or frightened.

While its color is distinctive, it is the shape of the caudal fin that sets this species apart more than anything else. There is a broad extension at the center of the caudal fin that is reminiscent of the shape of a plumetail platy’s caudal. When in spawning condition, the central rays of the caudal, including the extension, are red. The rest of the fin is black with a blue-white edge along the top and bottom. The body color is black in the ventral half and light brown in the dorsal half. The dorsal and anal fins are mostly black with a blue-white edge, and possibly a blue-white area close to the body. In short, this is a stunning fish well worth seeking out after you’ve worked with one or two other species. Because of its beauty, it is available regularly in the trade. In the wild, it is frequently found sympatrically with P. anjunganensis.

P. linkei

P. linkei is generally considered one of the easier species to maintain. Slightly larger than most, it can grow to 1¾ inches (4.5 cm) and is less demanding of blackwater conditions for successful maintenance—though its water should still be soft and acidic. There seems to be some confusion about this species. In some populations, the male develops a spade-shaped tail, while in others the tail is round. This could also be a feature of age, with the central rays of the tail growing as the fish gets older and larger.

The species is most easily identified by their mid-body spot or spots. These can be black or blue, but tend to be blue in more mature.