Spiny Whiptail Catfish (Loricaria spinulifera)

Meet Loricaria spinulifera, the spiny whiptail

Loricaria spinulifera is a slender whiptail catfish from the blackwater rivers of the Brazilian Amazon, and one of the less often seen members of its genus in UK shops. It is a flat, sand-coloured fish covered in small dark spots, with a tall dorsal fin, a wide head that tapers to a rounded snout, and a long, thin tail stalk that ends in a forked tail with a fine filament on the upper lobe. On fine sand under dim light it almost disappears, and that camouflage is a large part of its appeal.

The species was described in 2008 by Matthew Thomas and Lúcia Rapp Py-Daniel in the journal Neotropical Ichthyology, as one of three new Loricaria from the deep channels of Amazonian rivers. Its name comes from the Latin spinula, a small thorn, and means "bearing little thorns": a reference to the conspicuous thorn-like odontodes (tooth-like scales) on the top and sides of its head.

Read the names on the label

According to the original description, Loricaria is told apart from other whiptail genera by elongate, slender filaments on the lips and a small number of long, two-pointed teeth in the upper jaw. Within the genus, L. spinulifera stands out through strongly developed crests on the head and the plates in front of the dorsal fin, set with large thorn-like odontodes, a dense cluster of about 20 long papillae behind the upper teeth, and a solid dark brown upper head from the eyes to the tip of the snout, with large irregular spots behind it. The authors also note that the genus is poorly understood, with several undescribed species in museum collections, so identification of whiptails in the trade always carries some uncertainty.

Check what one purchase brings

One purchase supplies one live Loricaria spinulifera. Whiptails generally live peacefully with their own kind, so you can order two or three for a larger tank and let them share the sand. Our photographs show the shape and pattern of the species; every fish varies a little in the density of spots and in colour, and a newly moved catfish is often paler for its first days in a new tank.

Plan the order around the fish

• Size on arrival: fish are sold at a size suitable for travel and grow on in your tank.
• Adult size: the largest measured specimen reached 13.8 cm standard length (snout to the base of the tail). The tail fin and its filament come on top of that.
• Numbers: one fish lives contentedly alone; a small group spreads out over the sand and is fun to watch at feeding time.
• Timing: have the aquarium fully cycled before ordering and read our live fish delivery information so someone is home when the box arrives.

Understand where it lives in the wild

Most aquarium catfish come from shallow streams. This one does not. The original description reports that every specimen was collected by bottom trawl in the channels of large rivers, at depths from 1.5 to 28 m and between 10 and 750 m from the shore. Some specimens came from sand, mud and organic debris. The species is known from the Rio Negro, from the lower Rio Branco down to the mouth of the Negro, and from the lower Rio Jauaperi, in the Brazilian states of Amazonas and Roraima according to Wikipedia.

The Rio Negro is the largest blackwater river in the world. Wikipedia's blackwater river article gives its average pH as 5.1 ± 0.6 and its conductivity as 9 ± 2 µS/cm, close to rainwater, with only traces of calcium and magnesium. The authors noticed that fish from the deepest channels have smaller, more recessed eyes and fainter patterning than fish from shallower water, which is typical of fish living in dark, deep river beds. Our fish therefore come from a world of soft water, low light and soft bottoms, and the aquarium should echo that.

Note two survival tricks

Plan the aquarium around a long, flat catfish

A whiptail uses floor area, not height. What matters is a long, deep footprint of open sand where it can rest and sift, with shade above it. For a related, larger whiptail, Seriously Fish suggests a pair can be kept in about 75 × 30 × 30 cm (67.5 litres) and that a group needs more space. Because L. spinulifera is a deep-river fish that likes to spread out, we suggest a little more.

Run a three-step space check

1. Measure the floor. We suggest a footprint of at least 100 × 40 cm for one to three fish. OATA's catfish care sheet sets 80 litres as the starting point even for small catfish and notes that larger tanks are more stable.
2. Count the bottom dwellers. Corydoras, loaches and plecos all compete for the same sand and the same sinking food. Fewer, well-chosen bottom fish keep a whiptail fed.
3. Check the stock as a whole. Our tank mate checker helps you test a planned community before you buy.

Lay fine sand and soft cover

Sand is not optional for this fish. Wild specimens were trawled from sand, mud and debris, and whiptails take mouthfuls of the bottom to sift out food; the one stomach studied actually contained sand. OATA recommends aquarium sand or fine gravel for all catfish to protect their barbels, and Seriously Fish describes a soft, sandy substrate as preferred for Loricaria.

Divide the tank by zone

Leaf litter and wood also release tannins that tint the water tea-coloured and lower the pH a little, which suits a blackwater fish. Keep the light moderate; a deep-channel fish is most relaxed in shade.

Set water values for a blackwater fish

No one has published aquarium water values for L. spinulifera itself, so we start from the wild habitat and from care data for its relatives. The wild water is extremely soft and acidic. Seriously Fish gives 24–27°C, pH 5.6–7.8 and 1–20°dGH for Loricaria simillima, a whiptail from both black and white water, and Aquarium Glaser notes that blackwater forms of Loricaria are more demanding to keep and breed than whitewater forms. OATA's general catfish range is 22–27°C, pH 6.0–8.0 and 4–18°dH.

Compare the figures with our planning range

UK tap water ranges from very soft in Scotland, Wales and the north-west to very hard across much of the south and east. In a hard-water area, blend tap water with reverse osmosis water to bring hardness down gradually, and test before each change. Stability matters more than a perfect reading: a steady pH of 7.0 is far better than a swinging pH of 6.0. Our water matcher compares your water with what the fish needs, and our water chemistry guide and guide to pH for tropical fish explain the numbers.

Filter well and change water weekly

A sand-sifting fish lives in the layer where waste settles, so a clean floor is a healthy fish. Use a mature filter with moderate flow across the bottom and a gentle current near the surface for oxygen. Ammonia and nitrite must stay at zero, and OATA advises keeping nitrate no more than 20 mg/l above your tap water.

Follow a weekly routine

1. Test ammonia, nitrite, nitrate and pH at least once a week, more often in the first month.
2. Change at least 25% of the water, as OATA advises, and siphon detritus from the surface of the sand without digging deep.
3. Treat new water with a tap water conditioner and match its temperature.
4. Rinse filter media in old tank water, never under the tap.
5. Remove uneaten frozen food within a few hours; it fouls sand quickly.

Feed meaty sinking foods in the evening

The diet of wild L. spinulifera is known from a single fish: the stomach contained the hard body parts of caddisfly and fly larvae, organic detritus and sand. That fits what Seriously Fish says of Loricaria in general: omnivores that mainly eat aquatic invertebrates in the wild. Whiptails are slow, deliberate feeders, and Seriously Fish warns that they can lose food to more active tank mates.

Build one measured meal

• The base: a sinking pellet or granule such as our sinking bottom-fish granules, or a small wafer.
• The protein: frozen or live bloodworm and daphnia several times a week. Our Loricaria frozen food and live bloodworms both suit it. Thaw frozen food in tank water first.
• The extras: Seriously Fish mentions chopped earthworm and the occasional slice of cucumber or courgette for Loricaria.
• The timing: once a day, as OATA advises for catfish, shortly before the lights go out, dropped close to where the fish rests. OATA allows grazing bottom fish up to 30 minutes to finish; remove what is left after that.

Never rely on a catfish to live on leftovers. OATA is clear that catfish need their own sinking food.

Introduce it gently to a mature tank

OATA's floating method works well: lights off, float the sealed bag for 10 minutes, then add small amounts of tank water over up to 20 minutes before releasing the fish. OATA also asks retailers to double-bag catfish because their fin spines can pierce a bag. Practical Fishkeeping warns that after a long journey ammonia builds up in the bag and pH falls, so once the bag is open move the fish across promptly rather than dragging the process out. Handle it with a soft net or a container: the head odontodes and fin spines snag easily.

Use a first-week checkpoint plan

Watch for problems early

A healthy whiptail lies flat with fins neatly spread, breathes steadily and has a slightly rounded belly. OATA's warning signs for catfish include hanging at the surface, erratic swimming, faster or slower breathing, darker or paler colour, white spots, fluffy growths, weight loss and reduced appetite.

Pair each sign with an action

Choose calm tank mates

Seriously Fish describes Loricaria as very quiet fish that suit small characins, peaceful cichlids, Corydoras and loricariids that are not highly territorial, and notes they are generally amicable with their own kind. The aim is a tank where nothing takes its food or keeps it off the sand.

Screen each tank mate with a table

For more choices, browse our Loricaria whiptail category, the smaller Rineloricaria whiptails such as the Chocolate Whiptail Catfish, the full South American catfish category and our wider range of catfish and plecos. Our pleco care guide covers the shared basics of armoured catfish.

Learn how whiptails breed

Breeding of L. spinulifera has not been documented, but the genus has a distinctive method. In Loricaria the male guards the eggs at his mouth: Seriously Fish describes a male L. simillima carrying the clutch at his mouthparts for about 10–15 days and fanning it with lip movements, after a night-time spawning. Fry take 2–3 days to absorb the yolk, then accept brine shrimp nauplii, microworm and crushed dried foods, but are prone to starvation and sensitive to water changes.

Tell males from females

The original description reports two mature male L. spinulifera with the features of breeding males in the genus: a broader lower lip with shorter filaments and more papillae, rounder "mitten-shaped" teeth, slightly thickened pectoral spines and blunt odontodes on the pelvic and anal fin spines. In practice, a mature male shows a visibly larger, fleshier lower lip than a female. Seriously Fish suggests weekly water changes of 40–50% to condition Loricaria for spawning.

Answer Loricaria spinulifera buying questions

What is Loricaria spinulifera?

It is a South American whiptail catfish of the family Loricariidae, described by Thomas and Rapp Py-Daniel in 2008 from the Rio Negro basin in Brazil. The name means "bearing little thorns" and refers to the thorn-like odontodes (tooth-like scales) on its head.

How big does this whiptail grow?

The largest specimen on record measured 13.8 cm standard length, which leaves out the tail fin and its long upper filament. Including the tail and filament, an adult is noticeably longer, so plan the tank for a long, slender fish.

Is it a pleco?

It belongs to the same armoured suckermouth catfish family as plecos, but to the whiptail subfamily Loricariinae. Whiptails are flatter and slimmer, live on sand, and feed mainly on small invertebrates rather than grazing wood or algae.

What does it eat?

The only stomach studied held caddisfly and fly larvae, detritus and sand. Offer sinking pellets and wafers with frozen or live bloodworm, daphnia and similar small invertebrates, fed in the evening near its resting place.

Does it need sand?

Yes. Wild fish were trawled over sand, mud and organic debris, and whiptails sift the substrate for food. Fine, smooth aquarium sand protects the mouth and belly; sharp gravel is a poor choice.

What water does it need?

It comes from blackwater, which is very soft and acidic in the wild. In the aquarium we suggest 24–27°C, pH 6.0–7.0 and soft to medium water, kept clean and stable rather than chasing an exact number.

Can I keep it with cichlids?

Yes, with peaceful ones such as dwarf cichlids. Avoid boisterous or territorial fish that would take its food or bully it on the sand, and large predators that could swallow it.

Is it sold singly?

Yes. One purchase is one live fish. Whiptails get on with their own kind, so you can order several for a large tank.

Consult the care references

• Thomas, M. R. & Rapp Py-Daniel, L. H. (2008). Three new species of the armored catfish genus Loricaria from river channels of the Amazon basin. Neotropical Ichthyology 6(3): 379–394 — diagnosis, size of specimens, habitat, diet, breeding-male features and etymology.
• FishBase: Loricaria spinulifera — maximum size, depth range, air-breathing and conservation status.
• Wikipedia: Loricaria spinulifera — range by Brazilian state and IUCN status.
• Wikipedia: Blackwater river — Rio Negro pH, conductivity and mineral content.
• Seriously Fish: Loricaria simillima — tank size, water values, substrate, diet, behaviour and breeding of a related whiptail.
• Aquarium Glaser: Loricaria simillima bred — water, feeding and blackwater versus whitewater forms.
• OATA: How to look after catfish — general catfish water values, substrate, feeding, maintenance, acclimatisation and health signs.
• Practical Fishkeeping: How to acclimatise your new fish or shrimp — ammonia and pH in the transport bag.