u/KyleC66

Got a small group of these guys in today still young but super cool harder to find Chilatherina

Wanted to show off my 4 ponds for breeding this summer and the fish I bred. I don’t have exact numbers I’ll update this post when I have those numbers but the species I worked with were Melanotaenia Pygmaea and I got roughly 35 out of my group of 5 I put outside. I through 3-4 mops of praecox ‘pagai village’ in one of the ponds and it’s looking like I got maybe around 25 is the estimate. I had a group of Chilatherina Kali awalim where I actually lost the 4 of the 5 adults I put out there but looks like I have 10-15 of them growing out now. I did put out a group of pseudomugil mellis but with a cold snap a couple weeks ago it looks like I lost most of them. I had a couple other mops I put in the same praecox pond and maybe have 5-6 of other species in that tank but not sure what is what quite yet!

Saw a post recently where someone was trying to identify some Pseudomugil, so I figured I’d help out and put together this easy guide, along with a few common myths and things to know about the genus. The photos will be labeled and numbered to match the species below. These are the species currently available in the aquarium hobby. If you see something labeled as another species, I’d have my doubts. One common example is Pseudomugil paskai, which is not currently established in the aquarium hobby and is often used as a mislabel by transhippers. most of these photos are from myself but wanna give credit to Ryan lee for the reticulatus photo, wetspot for the signifer photo, and seriously fishy for the tennelus photo.

1.) Pseudomugil gertrudae (Spotted Blue-eye)
This is probably the most common blue-eye you’ll find in fish stores. They have a slender, semi-transparent silvery-blue body, sometimes with an overall golden-yellow wash, and their swim bladder is often clearly visible. They have two dorsal fins that sit close together, with the first being much smaller than the second. Their fins can be clear, white, silvery, or yellow and are covered in distinctive dark spots. The pectoral fins may have bright yellow, orange, or orange-red tips, while the scales often have dark edges that create a noticeable lattice or net-like pattern across the body. Males are generally more colorful and have larger, more extended dorsal, anal, and pelvic fins, along with heavier spotting on the body and fins. P. gertrudae has a wide and patchy natural distribution, so there can be a lot of variation between populations in color, body size, and fin shape. Most fish found in local stores are the standard aquarium strain, while ARU II and ARU IV are commonly available online.

2.) Pseudomugil luminatus (Red Neon Blue-eye)
This is another fairly common blue-eye and is often mislabeled as Pseudomugil paskai or “Paskai Rainbowfish.” P. paskai is not currently established in the aquarium hobby, so if you see that name being used, it is most likely a misidentification. Males are usually yellowish-tan, orange, or reddish, with thin brown outlines around the scales and a bright neon-blue stripe running along the upper part of the body from behind the head to the base of the tail. Their fins are generally yellow to pale orange and may have small black spots. The first dorsal fin has a narrow white edge and an extended white-tipped filament, while the tail has noticeable white tips on the upper and lower lobes. The pelvic fins are translucent yellow with long orange filaments. The head is usually pale gray or blue-gray, and the gill area often has a reddish glow due to the visible red gill filaments beneath the thin, transparent covering. Females are usually less colorful and more transparent, with mostly clear or lightly yellow fins and little to no spotting.

3.) Pseudomugil mellis (Honey Blue-eye)
This is a much rarer blue-eye and is usually found through select hobbyists or occasionally online. They are small, generally reaching around 1–1.5 inches, although most adults are closer to 1 inch. Males have a warm honey-colored body with lightly dark-edged scales that create a subtle lattice pattern. Their dorsal and anal fins have dark leading rays with creamy-brown centers and white outer edges. Males are easy to distinguish from females because they are much brighter and have longer, more extended dorsal fins. Females and juveniles are usually plain light amber with small, clear fins.

Special Care:
need low TDS soft water to thrive they will wither away if water is too hard.

4.) Pseudomugil furcatus (Forktail Rainbowfish)
This is another common blue-eye and one of the larger species commonly kept in the hobby. Their body is usually yellow-green, and both males and females have the species’ distinctive deeply forked tail. Males have clear dorsal and anal fins with narrow yellow edges, while their pectoral and pelvic fins often have a reddish tint. The tail lobes are yellow with dark edges along the top and bottom. Females are generally less colorful, with clear pectoral and pelvic fins and yellow tail lobes. Males are brighter overall and have longer, more extended dorsal fins. Because they are larger and more active than many other Pseudomugil, they generally do better with larger tankmates than the smaller blue-eye species.

5.) Pseudomugil signifer (Pacific Blue-eye)
This is a fairly common blue-eye and one of the more variable species. Fin colors can range from yellow to orange, and different populations may look noticeably different from one another. They have a slender, semi-transparent body that can range from pale olive or yellow to bluish, with fine dark outlines on the scales along the upper body. Their bright blue iris is especially noticeable and gives the species its common name. Many individuals have a row of around 10–12 reflective white spots running along the side of the body, while the gill covers and belly are usually silvery. Males are generally larger and more colorful than females and will rapidly raise and lower their fins while courting females or displaying to other males. Because this species has such a wide natural range, there can be major differences in color, markings, body size, and fin length between populations.

Special Care:
Some signifiers will appreciate harder water and even adding a little extra marine salt but I would ask the store or breeder what their gravity is.

6.) Pseudomugil cyanodorsalis (Neon Blue-eye)
These used to be around more often but are harder to find nowadays. They still occasionally show up in fish stores or through online breeders. Males have a striking metallic blue upper body, somewhat similar to the blue coloration of a Neon Tetra, while the lower half is translucent to yellowish-white. A thin dark line runs along the middle of the body toward the tail. The first dorsal fin is mostly clear with a dark outer edge and a small yellow patch near the base. The extended front rays and outer edges of the second dorsal and anal fins are black, while the rest of the fins are creamy yellow or white. The tail and pectoral fins are clear to slightly yellow with dark outer edges. Females are much plainer, with a semi-transparent silver-gray body, clear fins, and a pale white abdomen. They generally reach a maximum size of around 3.5 cm.

Special Care:
brackish fish need a gravity of 1.014-1.018 to keep them successfully long term

7.) Pseudomugil ivantsoffi (Ivantsoff’s Blue-eye)
This is a less commonly seen species, but it is often commercially farm-raised and occasionally available in fish stores. Males have a semi-transparent body that may show a bluish or reddish tint, along with bright blue eyes and strong red coloration on the dorsal, anal, and tail fins. The pelvic fins are usually pinkish, and some of the scales along the abdomen may have thin black edges. Females are mostly transparent and lack the strong red coloration of the males. Their fins are generally clear to lightly yellow, with yellow tips on the dorsal fins.

8.) Pseudomugil paludicola (Mangrove Blue-eye)
These are rarely seen in the hobby but are occasionally available through select breeders or online sellers. They have a mostly translucent body with a silvery head and abdomen. The pelvic fins are yellowish, and males often have yellow along the edge of the second dorsal fin. Females may show yellow near the base of the tail and along the front portion of the anal fin. Males are brighter and have longer, more extended dorsal fins, while females are generally smaller, have shorter fins, and lack much of the males’ coloration.

9.) Pseudomugil tenellus (Delicate Blue-eye)
These occasionally appear in fish stores or on wholesaler stock lists but are rarely imported unless specifically requested. Adult males usually have a translucent golden-brown upper body and a yellowish-brown lower body with a silvery sheen. Their scales are dark-edged, creating a noticeable lattice pattern. The fins are generally golden to burnt orange with pale yellow or white edges. The second dorsal and anal fins often have a curved pattern of small white spots, while the tail has a dark outer edge with a white fringe and the front edge of the pectoral fins is orange. Like other blue-eyes, they have a bright blue iris and a silvery gill and belly area. Color can vary depending on the fish’s mood, water conditions, diet, and overall health. Females and juveniles have similar body coloration but are less vibrant and have smaller, rounder fins without the markings seen in males.

10.) Pseudomugil reticulatus
More often than not, you’ll probably never see this species available, but I’m still holding out hope that there are some out there somewhere. Males have a light brown body with a silvery abdomen and swim bladder area, while the lower part of the chest is yellow and the head often has a reddish tint. The dorsal, anal, and tail fins have strong brick-red coloration, while the pelvic fins are pinkish-red and the eyes are an intense blue. Some of the scales along the abdomen have dark edges. Females have a much stronger net-like or reticulated scale pattern and are generally yellow-brown, with fine dark markings along the scales and fin rays. Their fins are more yellow than red, and their eggs are orange-red in color.

1st time finding this Reddit page but I can definitely say I like Rainbowfish. All photos are of my fish by me.

Edit:
Here’s the list of species of the photos in order
Melanotaenia sp. ‘Kali tawa’
Pseudomugil gertrudae ‘aruIV’
Pseudomugil mellis ‘snapper creek’
Melanotaenia praecox
Melanotaenia goldiei ‘dekai’
Melanotaenia sp. ‘Morehead river’
Chilatherina fasciata ‘Kali web’
Pseudomugil paludicola ‘timikia’
Melanotaenia vanhuerni ‘faowi village’
Melanotaenia wanoma
Melanotaenia bosemani ‘Kali fitri’
Pseudomugil cyandorsalis
Melanotaenia pygmaea
Chilatherina fasciata ‘Kali awalim’
Melanotaenia ‘Kali datu’