Yellownose skate

Where they come from

Yellownose skates (Zearaja chilensis) are cold-water skates from the southeastern Pacific and southwestern Atlantic, especially around Chile and Argentina. Think dark, chilly coastal shelves with sand and mud flats. That background basically tells you the whole story: they want cool water, lots of bottom space, and a life spent cruising the substrate more than "swimming" midwater.

Setting up their tank

Tank size is the make-or-break thing with skates. They don't need a tall tank, they need a huge footprint so they can turn without folding their fins and grinding their snout into corners. If you can't give them a wide, open bottom and stable cold water, I'd pass and pick a smaller benthic species.

Go with a big, low aquascape. Minimal rock, and keep it locked down so nothing shifts if the skate bumps it. I like leaving the center open like a runway and keeping any structure tight to the back/sides.

• Footprint first: wide and long beats tall every time
• Substrate: fine sand (not crushed coral). Coarse stuff can scrape the belly and fin edges
• Decor: smooth, stable, and not pointy. No sharp live rock ledges at skate level
• Flow: enough to keep oxygen high, but avoid blasting the bottom where they rest
• Lid: they can startle and slap water. A tight cover saves headaches

Filtration has to be overbuilt. These guys eat meaty foods and produce serious waste, so you want heavy skimming, big mechanical filtration you can clean often, and lots of biofiltration. If your water gets "fishy" between maintenance days, you're under-filtered.

Use oversized intakes and cover everything with strainers. Skates investigate with their face and fins, and an unguarded intake is an accident waiting to happen.

What to feed them

They are basically bottom hunters that key in on scent and movement. Mine did best with a varied rotation of marine meaty foods. If you feed one thing over and over, you'll eventually see sluggish feeding, picky behavior, or nutritional gaps.

• Staples: pieces of squid, shrimp/prawn, scallop, marine fish flesh (not freshwater feeders)
• Great variety: clam, mussel, crab chunks (shell removed), smelt/silversides in moderation
• Enrichment: occasional live foods like shore shrimp can help trigger reluctant eaters (quarantine if possible)

Training to tongs is your friend. It keeps fingers safe, lets you target-feed, and reduces the chance tankmates steal everything. Start by wiggling food on feeding tongs right in front of the snout and be patient. Once they learn, it gets easy.

How often? Smaller/younger skates usually do better with smaller meals more frequently. Big adults can handle larger meals a few times a week. Watch the body shape: you want a filled-out disc without a sunken look behind the head, but not a bloated belly that drags.

How they behave and who they get along with

Yellownose skates are generally calm and spend a lot of time resting on the sand. They will bury a bit, shuffle around at dusk, and pounce on anything that smells like food. They are not "community fish" in the usual sense, but they also aren't looking to pick fights.

The main compatibility issue is food competition and fin damage. Fast, pushy fish will steal meals and stress the skate. Nippy fish will chew fin edges. And anything small enough to fit in the mouth is on the menu eventually.

• Good tankmates: large, non-nippy cold-water fish that don't outcompete them at feeding time
• Avoid: triggers, puffers, large wrasses, and anything known for picking at fins
• Avoid: aggressive sharks/rays that crowd the bottom and turn feeding into a brawl
• Avoid: small fish/inverts you actually want to keep long-term (they will get eaten)

Give them space and predictable routines. They learn the tank and your feeding schedule, and a settled skate acts very different from a new one that's being chased around by boisterous tankmates.

Breeding tips

Breeding is possible in captivity, but it is a long-game project and you need room for adults. They're egg-layers (you'll see tough "mermaid's purse" egg cases). If you ever get a mature pair, the best thing you can do is keep the system stable, keep them well-fed, and avoid stressing them with constant rearranging or aggressive tankmates.

• If you find egg cases: protect them from scavengers and strong mechanical intakes
• Gentle, steady flow is better than blasting the eggs around the tank
• Keep a log of dates - incubation can take a long time in cold water

Common problems to watch for

Most issues I see with skates trace back to three things: temperature, water quality, and physical damage. Fix those, and you avoid a lot of heartache.

• Heat stress: rapid breathing, listlessness, refusing food, hanging in high-flow/high-oxygen spots
• Ammonia/nitrite exposure: red patches, lethargy, heavy breathing, sudden decline after a big meal or filter issue
• Fin edge damage: fraying or white margins from nips, rough substrate, or scraping tight corners
• Mouth/snout abrasions: from sharp rock, uncovered intakes, or panic dashing
• Feeding problems: food theft by tankmates, or a skate that never settles in after shipping

If a skate stops eating, don't just keep tossing food in and hoping. Check temperature first, then oxygenation, then test ammonia/nitrite right away. After that, watch the tank at feeding time and see if tankmates are bullying or stealing. In my experience, behavior tells you what's wrong before test kits do.