Gourmet worm food

 The last time I got a decent photo of the fat polychaete worm in my tank, 6 months ago, she* was about 8 to 10 inches long. Now she's over a foot long, still fat, still hungry.

Ragworm, aka king ragworm, Alitta virens, Nereis virens

She eats shrimp pellets, taking big gulps before she retreats under the sand. But she really loves delicate green algae. When I bring home sea lettuce, she comes out to get her fill. When I haven't found fresh greens, I give her a square of roasted seaweed; human food, containing only the seaweed, a hint of oil, and salt. And for this, she'll come out of hiding and even climb the wall to get it before it floats away.

"Do I smell green?"

I keep trying to get a photo of her four eyes. This time, an algae spot (not the kind she eats) on the glass hid her face. Maybe next time.

*She, because she's a polychaete, so I call her Polly. Which needs a feminine pronoun.

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La última vez que pude sacar una buena foto del lombriz poliqueto que vive en mi acuario, hace 6 meses, medía aproximadamente 20 o 25 cm. de largo. Ahora, ya pasó los 30 cm. Sigue gordita, sigue hambrienta.

Fotos: poliqueto Alitta virens.

Come bocaditos de camarón, llenándose la boca antes de volver a esconderse bajo la arena. Pero lo que de veras le gusta es el alga marina verde. Cuando le traigo "lechuga marina" Ulva sp., sale y come hasta llenarse. Y cuando no encuentro algas frescas, pues le doy de esas algas que venden para humanos; alga marina verde, tostada con un poco de aceite y sal. Y para eso, "Polly" (así le llamo por ser poliqueto) es capaz de extenderse más y hasta trepar a la pared para comerla antes de que se la lleve la corriente.

Sigo tratando de sacar una foto de sus cuatro ojos. Esta vez, una mancha de alga amarilla que crece en la pared se interpuso. Será para la próxima.

Look at the camera, Polly!

I keep trying to get a face shot of my big ragworm, "Polly", with no luck. It's rare that she faces the glass, even when I sneakily put food right in the best location up against the glass. And when she does look my way, she immedidately opens up that big mouth to show me her "tonsils". I want the eyes, all four of them.

So. Side shots, with maybe one eye.

Two fat palps, two small palps, four antennae on each side of the head. The parapodia (the paddle "feet") on each segment have 4 or 5 fat "toes" and two needle-thin hairs.

One eye visible.

She likes eating algae, both red and green. Here she's grabbed an algae-covered blade of eelgrass. She dragged a couple of inches of it down into her burrow.

Looking down her throat.

That stripy chin! Almost looks like she's growing a beard.

I'll keep trying.

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Sigo tratando de sacar una foto de la cara de mi anélido poliqueto, "Polly", sin suerte. Es muy raro que se acerca de frente a la pared del acuario, aun cuando coloco sus alimentos favoritos justo en el sitio más favorable. Y cuando por casualidad se arrima, me abre su boca enorme para enseñar el fondo de su garganta. ¡Quiero ojos, los cuatro ojos!

Pues, aquí hay fotos otra vez de perfil.

1. Dos palpos gordos, dos pequeños, y cuatro antenas de cada lado de la cabeza. Los parapodia (las "patas" o paletas) en cada segmento tienen 4 o 5 setas gordas (como si fueran dedos) y dos setas agudas.
2. Aquí se ve un ojo.
3. Le gusta comer algas, o rojas o verdes. Aquí agarra una hoja de hierba marina Zostera, cubierta de alga. Jaló unos cuatro centímetros de la hoja dentro de su túnel bajo la arena.
4. Enseñándome la garganta.
5. ¿Ese cuello! Casi parece que lleva barba.

Seguiré tratando de lograr una foto de frente.

Of paddles and orgies

One of the great things about a blog is that it serves as an aide-memoire; what I saw, when, where; it's all there, and searchable. So I was able to review my experience with the big polychaetes.

I find that I brought home a pair, both under 4 inches long, from the White Rock beach, in the first week of October, last year. Digging through the sand, then, I found a worm that stretched out to 7 inches long.

It's been almost seven months since then. Those three have turned into eight, at least twice the size of the biggest one, back then, plus a few more 4-inch specimens.

I had narrowed the species down to Nereis, possibly vellixosa, which grows to about 6 inches. I'll have to revise that. I think, now, that they are Neries vixens, recently renamed Alitta virens, or possibly A. brandti, which is also common and virtually indistinguishable from vixens. Both of these, the Giant piling sea-nymph and the Giant clam worm, grow to at least a foot, like mine.

One thing that confused me is that the parapodia on these big worms are different from those on the smaller ones. Those are like pencil points with hair on the end; these are triangular paddles, with no hair visible.

Yesterday's worm, with non-hairy paddles.

Last October's worms, with hairy pencil points. The smaller ones I have now are like these.

A website from Wales reassured me that I was on the right track; their A. vixens, which they call King Ragworms, have paddles, although near the head end, the hairy points are still visible. (Look at the middle of the second worm for the paddles.)

I found the explanation in Kozloff. He writes, about N. vexillosa,

"... the sexually mature phase of this species is rather unlike the phase typical of mussel beds and bay habitats. The fleshy parapodia become expanded into paddlelike structures for swimming, and periodically during the summer the ripe males and females swarm at night near the surface. ... The worms do not survive long after their nocturnal orgy, during which they simply spew out their eggs or sperm through openings that develop in the body wall."

The Giants swarm, too. Kozloff says it's an "exciting spectacle.I can imagine; think of yesterday's video, but with dozens of worms in the open water, thrashing about in the moonlight.

So I've sent my critters out into the big world, just in time to !!PARTY!! I'll have to keep an eye on the few that I kept at home.

I found a couple of interesting head shots of these worms; interesting, if not exactly cute. PZ picked up one from an underwater image competition, back in 2006. The original site is no longer available, but the photos are still on Pharyngula. The third one down is Nereis.

And Ugly Overload has two face shots, from Alexander Semenov. This second link goes to his Flickr page; it's worth clicking over there to see the rest of his macro photos. Amazing and wonderful!