A forest of coral, with beautiful bivalves

I started volunteering at the zoo in November 2003, in weather much like this dark, rainy, gusty April we’ve been having. On the darkest days, I’d find myself standing in front of the live-coral tank in Discovery Bay, drinking in all the color and light of the underwater rainforest.

When that tank sprang a leak and went away, I had to go without my coral fix for months — until this bigger, better replacement arrived a year or two back. It takes time to build up a saltwater aquarium into this resplendent spectacle, and it’s always evolving. Veteran inhabitants like our “Finding Nemo”-style clownfish — see him floating in that central cave? — and his fishy sidekick Dory the blue tang share space with newer arrivals like my new favorite clam, the azure fellow down in the lower left corner. (There’s at least one more of him elsewhere in the aquarium, if you look closely.)

Like so much sealife, this beautiful bivalve has multiple names: The zoo labels it a boring clam because it bores down into the rock by releasing acids, then anchors itself to a chosen spot. But it’s also known as a burrowing, crocea or crocus clam, and the species’ coloration can range into oranges and golds. (Detailed information about Tridacna crocea is surprisingly scarce online, but I eventually found some from an aquarium store and reef hobbyists.) The crocea requires “intense” lighting and feeds itself via photosynthesis, like a plant. This one must have been “burrowing” as I watched it last week; using its byssal muscle and attaching itself to the floor with byssal threads or filaments, it opened and closed like a butterfly’s wings, almost appearing to breathe.

I can’t even count all the corals, fish and other creatures living in here, but one of my favorites is hiding leftward of the crocus clam in the photo below: the blue-dot or blue-spotted jawfish, which has dug itself a hole and is peering out, as is this species’ wont. (Here’s a closeup, too.) We have three new jawfish in here now, digging burrows and sometimes even swimming.

The world’s oceans, and this aquarium, contain countless varieties of coral with a host of melodious names: both the rocklike hard corals (staghorn, velvet stone, pineapple brain, trumpet) and the plantlike soft corals (mushroom, toadstool, bubble). Like its relative the floral-looking anemone, a coral is an animal, symmetrically arranged around a central mouth. Unlike anemones, individual coral polyps press together to form ever-growing colonies — ever-growing, at least, until environmental factors lead to coral bleaching and threaten the entire ecosystem of creatures that take shelter in the reef. Home to a quarter of all marine life, these reefs are dwindling in tropical seas worldwide. It’s not just their beauty that makes them worth saving.


Snakes on the brain

In the weeks since the Bronx Zoo’s cobra escaped, started tweeting and was finally restored to her enclosure, my preoccupation with reptiles has spiked a bit. I spent some quality couch time Sunday with the zoo’s fact sheet on snakes, meditating on their coolness (a jaw that unhinges while held together by ligaments!) and trying to pick a favorite out of the four types of serpents I’ve demo’d at the zoo. I’ve written here about my close encounters with Sylvia the milksnake and Bita the Western hognose, and I’ve alluded more briefly to William, the zoo’s increasingly huge but consistently tranquil bullsnake. But more often in the past few months, including last week, I’ve been scheduled to demo Cornelius the cornsnake.

In the wild, all Cornelius’ relatives live on the East Coast. Also known as red rat snakes or red racers, cornsnakes have ruddy-orange backs, with a more golden Indian-corn pattern on their bellies. Half the size of a full-grown bullsnake, they’re a midsized and manageable 2 to 4 feet long. At the zoo, they eat a single mouse (frozen, then thawed) each week. Like other constrictors (see how tightly Cornelius twines round this volunteer’s wrist), they have ways of pretending they’re venomous to scare off predators: When threatened or upset, a cornsnakes will vibrate the end of its tail as if to imply, “Watch out, I’m a rattlesnake.” But it’s all for show.

If my fondness for snakes seems in any way peculiar, consider this photo of William the bullsnake gazing up at my fellow volunteer Bob. I had an especially soft spot for William in my early snake-wielding days, when he was still cornsnake-sized and notably docile. Back then the zoo’s other young bullsnake, Draco, could most charitably be described as extra-wiggly. The bullsnake is the largest snake in Minnesota at 4 to 8 feet long, and now that both William and Draco have reached adulthood, they’re quite a bit heavier to hold but equally mellow. Bullsnakes are named for their hiss, which allegedly sounds like a bull snorting, but I’ve never seen these guys get that agitated — not even Draco at his most wiggly.

Sea turtle reborn

Ten minutes before leaving the zoo yesterday, I was chatting with a fellow volunteer in Discovery Bay when a distant flash of movement caught my eye. Across the room, in the shark tank, one of our two injured sea turtles was swimming. I dashed over to see which one, and it was Mardi, the Kemps Ridley turtle who almost never dips below the water’s surface.

Both Mardi and our green sea turtle, Bay, are “boatstrike” turtles whose injuries limit their buoyancy and mobility. A bunch of lettuce anchored to the tank’s floor has been known to lure Bay down into view at feeding time, but I’d never seen Mardi swoop across this landscape of coral and fishes before; I was excited enough to spot him up at the surface last summer, and I wrote about him then, too.  At the viewing window yesterday, I found a couple of aquarium staffers who explained that Mardi, who likely took a boat’s propeller to the head in his native waters off the shore of Louisiana, had seemed almost brain-damaged ever since he came to the zoo by way of a North Carolina rescue facility several years ago. But on the advice of turtle experts elsewhere, Mardi has been taking “supplements” in his diet lately, including milk thistle, and as of Tuesday he had recovered his appetite and was behaving almost normally.

I couldn’t help thinking of the rare patient who emerges from years of coma or that 1990 movie “Awakenings” with Robin Williams and Robert DeNiro, where a miracle cure brings patients out of a stupor — for a while. It’s too soon to know whether Mardi has become a new turtle, or if this sudden burst of energy is just a random blip on the radar. What’s certain is that sea turtles and motorboats don’t mix well, and that zoos and aquariums serve as a valuable refuge when these large and lovely reptiles survive the collision.

Fuzzy, small and faithful

April Fool’s Day marked the opening of the zoo’s family farm and the official start of its spring babies season. But on the last day of March, most of the baby action was still indoors — especially in the Tropics, where two-week-old agoutis were on exhibit. My camera and I gravitated to the South American end of the trail, looking for the new tiny rodents. I came for the agoutis but stayed for the two adult golden lion tamarins — equally tiny monkeys dwelling in the same exhibit’s treetops.

But first, the ground-dwelling agoutis. The two babies were so shy and lightning-quick that my camera caught a mere blur of them, but because they’re born “precocial” — just a miniature, self-reliant version of their fully formed adult selves — they really don’t look much different from their parents, seen below. And even the largest adult agouti won’t top 9 pounds.

Zoo lit informs volunteers that the Greek genus name for agoutis, Dasyprocta, means “fuzzy butt” and that they’re “the basic diet of South American carnivores” — including, at least once, a biology professor in-law of mine who makes annual research trips down there and graciously eats what the natives serve him. In the rainforest, agoutis may gather in large groups to feed, following along beneath tamarins or other monkeys and browsing on fruit and nuts that the primates drop from the trees. Agoutis are the only animal that can chew through the woody pod of a Brazil nut, releasing and spreading the seeds that nestle within.

Before the zoo’s Creatures under the Canopy exhibits opened several years ago, I confused the word “tamarin” with tamarind, the African evergreen fruit tree. The four varieties of lion tamarins (with “manes”) also include golden-headed, black-faced and just plain black. The golden ones weigh less than two pounds apiece, and they live in what remains of eastern Brazil’s rainforests, mostly in a preserve near Rio de Janeiro. Logging and agriculture have decimated the rest of their coastal home.

Golden lion tamarins and agoutis have more in common than a shared habitat and zoo exhibit. One is a primate and one is a rodent, but both form monogamous pairs and give birth to twins. In the wild, a tamarin father and other adults participate in caring for babies. At the zoo, our tamarin couple may or may not breed; the female reportedly suffered a recent miscarriage. Here they nestle together, endearing and clearly devoted.