Spawning Report: Oreichthys crenuchoides (Drapefin Barbs)

Oreichthys crenuchoides (Drapefin Barb) Spawning Report

Submitted by Patchin Crandall Curtis

Background: Drapefin barbs are diminutive (1.5-2”), peaceful fish from Eastern India where they inhabit slow-moving water flowing over open land. They are a pale, pearlescent pink color with dramatic black markings with shocks of yellow in the dorsal fins. They are relatively inactive except when spawning and don’t require a lot of space. The males develop long, flowing dorsal fins that remain recumbent until males display to each other. The females are much smaller than the males.

Colony: The original breeding colony of 10 fish was purchased from Invertebrates by MsJinkzd in December, 2017. As they matured, it became evident there were only 3 females, so an additional 6 wild-caught fish were purchased from The Wet Spot in March, 2018. The original colony was quarantined with much larger, more boisterous barbs (not recommended) and there were a few losses. They stabilized as soon as they were moved into a species-only tank. At the time of this spawning, there were 7 pairs of adult fish in the colony of which about 4 are F1 offspring of the original colony.

Spawning Behavior: These fish spawn exclusively at dusk. The males circle each other in gorgeous displays and chase females into secluded corners and java moss clumps. No fish ever seem to be harmed during the vigorous displays. Spawning is in the typical curved clutch fashion of barbs. Side-by-side, the male will curve himself around the female, and then the clasped pair will slowly float upward into an inverted position. Drapefins are egg scatterers. The eggs are not adhesive and must fall into crevices or plants to avoid being eaten. Seriously Fish reports that eggs are laid on the underside of broad plant leaves or solid surfaces while swimming in an inverted position, but I have not observed this behavior. Given that the eggs are not adhesive, it is puzzling to suppose that eggs would be laid on the underside of leaves. Single spawns seem to produce a relatively small number of eggs (perhaps 2-6 per day per female) consistent with the small size of the females who never become very round. These ladies retain their svelte figures. Seriously Fish describes Drapefin Barbs as continuous spawners, but in my house they seem to be seasonal spawners exhibiting little interest in spawning during the summer months.

Tank Setup: Three bare bottom 10g tanks were set up with heaters, sponge filters, and plastic spawning boxes about 8” X 4” X 4” in size. Each box contained a layer of blue marbles about 2 deep covered by a layer of black needlepoint canvas (to prevent them from diving into the marbles to eat the eggs) and topped off with 3 spawning mops of dark olive-green yarn.

Water Parameters: The water was soft (~3-5 dH GH, ~1-3 dH KH), clean (~2.5 ppm nitrates), and neutral (pH 7.4-7.6). The sponge filters were not mature, so 75% water changes are performed daily with a few drops of Aqueon Ammonia Detoxifier. Seriously Fish recommends a temperature range of 74o – 81o F for Drapefins. The breeding colony had been maintained at a temperature of 76o – 77o F. The 10g breeding tanks had heaters set to 76o F to maintain the same parameters. One of the heater’s calibration was off, and the water in that tank was 73o F.

Spawning: On 8/29/2019 three pairs of fish were netted out from the breeding colony and placed in the 3 10g tanks. The pair with the cooler water immediately started producing eggs. Eggs measured 1.2 mm in diameter. I lowered the temperature on the other two tanks by 2o per day to stabilize at 74oF, but only the same pair with initial cooler water was producing eggs. The fourth evening I forgot to plug the heaters back in after the water changes, and the next morning the temperature had drifted down to 69oF and a second pair produced 2 eggs. On 9/3/2019 I plugged the heaters back in raising the heat to 71-72oF in two of the tanks and 74oF in the third tank. On 9/4/2019 collected 4 eggs from the pair that had not as yet produced any eggs.

A fourth breeder box was placed in the 38g tank on 8/31/2019 to see if a group of 4 male and 4 female Drapefin Barbs would spawn in the box without all the eggs getting eaten by the others. It took a few days of lowering the tank temperature from 77o to 74o F. On the third day 2 eggs were collected from the box. The single panda barb in the tank seemed to be disrupting the drapefin barbs, so I removed him. The next day, on 9/4/2019, I pulled 7 eggs from the community tank, and on the day after 20 eggs implying that eggs may have been contributed by all 4 pairs.

Conclusions About Temperature: Drapefin Barbs seem to thrive best when kept at subtropical temperatures with 74oF being ideal. I would rewrite their range to be 68o – 76oF. To induce spawning, a cool water change of 65o – 68oF followed by stable temperatures of 74oF seems to result in the best egg production.

Hatching Eggs: Eggs were placed in a 6g XL Kritter Keeper at 75oF to hatch. The first eggs were introduced on 8/30/2019 and 2-6 more eggs per day after that from the three different breeding pairs and then the bonanza of 20 eggs from the larger colony on 9/5/2019 for a total of about 50 eggs.

On 9/3/2019, 4 days after the first eggs were placed in the hatching tank, 3 larval fish appeared clinging to the tank walls. On 9/4/2019 12 larval fish were observed clinging to the tank walls. Upon adding a splash of rotifer culture, the fry became active, with a few swimming in the water column but most of them scooting along the tank walls to chase rotifers. By 9/10/2019 at least 20 larval fish were present with about half of them free swimming. The eggs continued to hatch with about 4-5 newly hatched larval fish ((discernable eye balls with a clear wisp for a body and no discernable stomach or yoke sack) spotted per day. By 9/13/2019 at least 30 fry were observed, and on 9/14/2019 the number appeared to be over 40. A large number of larval fish seem to be hiding in the substrate only popping up now and again to grab a rotifer or paramecium, so the total number of fry could be much larger than 40.

The hatch rate appeared to be 100% consistent with the Rohan, Panda, and Rosy Barb spawnings.

Raising Fry: No food was fed until the larval fish were observed hanging on the sides at which time a small splash of rotifer culture was added. After another day vinegar eels were added to the menu, and then later euglena. When the oldest fry were about a week old, their diet of rotifers and euglena was augmented with a slurry of vinegar eels, microworms, and 50-100 mm Golden Pearls fry powder added to the tank with a pipette to control the volume and distribution. On 9/13/2019 they received their first paramecium, and on 9/14/2019 their first Blepharisma.