Taxonomy
Order: Siluriformes
Suborder: Loricarioidei
Family: Loricariidae
Subfamily: Hypostominae
Genus: Hemiancistrus
Species: not described yet
Description
Hemiancistrus sp. L128 is a large-growing pleco commonly known by the synonym Blue Phantom Pleco. This species can reach over 25 cm in length and therefore requires a considerable amount of space in the aquarium.
The overall base color is olive-green-gray with a blue tint. Bright white/yellow/light blue spots cover the entire body, giving this pleco a very colorful and interesting appearance. Males and females develop yellowish odontodes (dermal teeth) on the gills and pectoral fins. Males sometimes exhibit a light odontode growth next to the dorsal fin.
This fish can exhibit aggressive behavior toward its own kind, especially males. Otherwise, this species is peaceful toward most other fish.
Hemiancistrus sp. L128 should not be confused with the described species Hemiancistrus subviridis L200, which certainly belongs to the same genus. The body shape and markings are very similar, despite a very clear color difference. For example, the L128, especially when young, has a blue-green base color, while the L200 exhibits a yellow-brown coloration. Furthermore, young specimens of the L128 have a white spot pattern or lighter edges on the edges of the dorsal and caudal fins, which are completely absent in the L200. The lighter edges on the dorsal and caudal fins of the L128 do disappear with age.
Both species inhabit the upper reaches of the Rio Orinoco, but the L200 appears to occur much further upstream, above the tributary of the Rio Atabapo, as far as the Rio Ventuari.
Furthermore, the L128 can easily be confused with Hemiancistrus sp. L467 or Baryancistrus demantoides L200 Hi Fin.
Distribution and habitat
The L128 pleco lives in the warm, oxygen-rich rapids of the Rio Orinoco, near Puerto Ayacucho. This city is located on the border region between Venezuela and Colombia in the state of Amazonas.
The Orinoco River is a major river that originates in the Sierra Parima, near the border with Brazil. This river flows through Venezuela and Colombia.
The Orinoco River in the area where L128 lives is very warm, 28 - 33 °C, and fast-flowing. The water is soft (electrical conductivity <50µS/cm) and has a pH between 6,5 and 7,0.
These animals live here among and under rocks.
Hemiancistrus sp. L128 shares its habitat with species such as Peckoltia sabaji L124, Dekeyseria scaphirhyncha and Pterygoplichthys gibbiceps.
Diet
Hemiancistrus sp. L128 is omnivorous, meaning it eats both plant matter and animal protein. In the wild, its diet consists primarily of crustaceans and insect larvae, as well as various types of algae.
What should I feed my Hemiancistrus sp. L128?
In captivity, this species can be fed a variety of processed and frozen foods. This fish isn't necessarily a picky eater, provided it's healthy and feeling well. Fresh vegetables, such as zucchini or sweet potato, can also be fed.
I feed my L128 plecos with EBO Spirulina soft granulate, EBO Artemia soft granulate, Futterdose Krill granulate, Dr. Bassleer Biofish Food Chlorella and sometimes with Futterdose Manabi soft granulate and EBO Veggie sticks.
Aquarium
Because this fish grows quite large, the aquarium should be at least 150 cm long. Depending on the number of specimens and their size, tanks with 200 cm are preferable. Males can be very territorial and fight over their hiding and breeding spots, especially against conspecifics. There should always be more caves or hiding places than the number of plecos in the aquarium. In addition to breeding caves, large stones and driftwood can be used to create barriers. Sand works very well as a substrate.
In addition to good filtration, a streaming pump and an air stone are essential for an L128 aquarium. Dimmed light helps to see the shy fish more often outside of their caves during the day.
This pleco can also be kept in community aquariums as it does not show aggression towards other fish and has no special needs in feeding.
Sex difference
Determining the sex of Phantom plecos can sometimes be tricky, especially because females can display many male characteristics, such as spiny odontodes on their fins and gills. Sometimes they even have quite masculine heads. I hope this post will help you determine the sex of your Hemiancistrus sp. L128.
How to identify the sex of Hemiancistrus sp. L128 by looking at them from the side?
When you look at the animals from the side, it is noticeable that the female appears to be slightly higher and less flat than the male.
What differences between the sexes are visible in the head?
As mentioned, the head shape isn't the best indicator of sex in this pleco. Both males and females have a fairly similar head silhouette when viewed from the side.
How can you determine sex at the gills?
The odontodes on the gills are very prominent in both sexes. Although males generally tend to have longer ones, there are females that seems to be as spiky as males.
How can you determine sex at the pectoral fins?
The odontodes on the pectoral fins are more developed in adult males. It's not a good way to sex young individuals using these odontodes.
How can you determine sex by the tail?
In most cases, females exhibit a smooth surface of the hind body part. In males, rows of small odontodes can be seen, especially next to the dorsal fin.
How do you determine sex based on body shape of Hemiancistrus (top view)?
From above, the overall body shape is more visible. Females are more curvy and have their widest part at the waist/belly region (hips). Males tend to be broadest at the shoulders.
What gender differences are visible in the head from above?
From above, the heads look quite similar. Females generally have a somewhat rounder head, but are not significantly smaller than males. The only outstanding difference can be seen around the gills. Males have thicker gill flaps, which house the odontodes. These are noticeable as small bumps on each side.
How can I determine the sex of the Hemiancistrus sp. based on the papilla?
For me, the underside reveals the most about the sex of the Blue Phantom Pleco. Males have a small, pointed papilla, where as females have a round broad papilla. This female also shows yellow spots around the genital papilla.
Reproduction and breeding
Like almost every other pleco, this species is also a cavity spawner. Males take care for the eggs until the larvae hatch and deplete their yolk sacs.
For breeding, it might be best to separate compatible pairs into separate breeding tanks. The breeding tank should be equipped with two or three breeding caves, appropriately sized, a few hiding places, and a streaming pump. The water should be well-oxygenated and warm (around 30 °C). Large weekly waterchanges can stimulate this pleco to spawn. Soft, osmosis water will put these fish in the breeding mood.
The most important thing is not to stress the breeding pair during or after spawning, as males tend to eat the eggs when stressed. This species tends to show no interest in each other for long periods and seems to start tunneling out of nowhere. It usually doesn't take long for them to lay eggs (1 - 3 days).
For this species I personally use round breeding caves with a length of 28 cm and a diameter of approximately 8 - 9 cm.
