Tag Archives: eggs

Workers find plenty to like about their feathery friends

Published January 4, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
Albatross

Albatrosses at Midway are curious about volunteers on the atoll, but because they evolved without land predators, are unafraid. ©Susan Scott

MIDWAY ATOLL >> Why do 18 people with a range of backgrounds pay their own expenses to count albatrosses on a remote atoll over the holidays? We’re nature lovers, of course, but we have another link: We think living with albatrosses is fun.

Everyone marvels at the goose-size birds’ boisterous songs and delirious dances, but albatrosses have nearly endless endearing behaviors. When I asked each of my five team members to name their favorite, the response was the same: “I have to pick just one?”

Martha chose egg talk. Every once in a while a brooding bird stands up, lowers its beak to the egg and murmurs, “Eh, eh, eh.” No one knows what this means, but it’s likely voice recognition between parents and offspring, crucial when mom or dad return with a meal to a colony of hundreds of thousands of wandering, identical-looking chicks.

Craig likes shift change. For the 63-day incubation period, albatross couples take turns keeping their egg warm, the on-duty bird sitting for up to three weeks. Yet even though the sedentary bird’s digestive tract is empty after the first few days, the sitter hates to quit work. The resulting circling, murmuring and nudging by the relief partner goes on for so long that witnessing the actual transfer is a noteworthy event.

Ann-Sheree is fond of the way couples groom each other’s feathers in affectionate nibbles with those big sharp beaks. The recipient closes its eyes and turns its head and neck as if getting a massage. Then it’s the other’s turn for a tender feather fix.

Breck and Luke picked as their favorite behaviors some albatrosses’ show of utter indignation when annoyed. Each bird has its own personality, and a few are quick to issue a snappy bill-clacking warning to back off when a bird dances too near a nest or a human steps too close. A few plucky individuals deliver a peck.

These seldom connect, but when they do it’s a pinch of a pant leg or, at worst, a scratch on the skin. Afterward the bird looks smug, as if to say, “Well, I warned you.”

As for me, I love that albatrosses, lacking natural land predators, aren’t afraid of me. When I sit on the road taking pictures, young walkers often stop by and gently touch my shoe, shirt, camera or arm. What are you? I imagine them thinking as they stare up at my face. Looking into the eyes of an albatross as it calmly gazes back makes me happy to be alive. I know I speak for us all when I say that working at Midway is the privilege of a lifetime. It’s also really fun.

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Fish reproduction an intriguing process

Published September 1, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

In 1958 my mother went into labor during a Labor Day picnic. The pandemonium that ensued, ending with the delivery of a healthy baby boy, made such an impression on my 10-year-old mind that since then I’ve linked Labor Day with the labor of giving birth.

Today, given my interest in marine life, I’ve extended that link to include the birth of fish.

Fish don’t deliver live babies in the way of us mammals (sharks and seahorses being exceptions), but in a massive ocean teeming with predators, fish have methods of producing offspring that are a category of labor all its own.

The most common kind of fish reproduction is called broadcast spawning, a system in which males and females release sperm and eggs into the water. And that’s the end of it for the potential parents. Spew and split. Job done.

The chances of free-floating eggs and swimming sperm connecting on a coral reef is small, and offshore even smaller. But fish have ways of upping the odds. One is to produce an enormous number of eggs and sperm. This is where labor comes in. When it’s time, as dictated by moon phase, day length, water temperature or something we don’t know, female reef fish produce tens of thousands of eggs and males manufacture millions of sperm.

Open ocean species churn out even more.

The queen of egg production is the ocean sunfish (scientific name Mola mola, hence the common name, mola). In one 4.5 foot-long female, researchers found an estimated 300 million eggs in her one ovary, several orders of magnitude greater than the average broadcast spawner. Since molas grow to about 6 feet long, it’s likely that a full grown female would have even more eggs.

Broadcast spawners’ tiny floating eggs and sperm become part of the drifting plant and animal soup known as plankton, the beginning of the food web. Plankton eaters gobble up most of those sex cells, but some fulfill their destiny of continuing of the species.

Researchers measure a fish’s reproductive effort by comparing the size of its gonads to the size of its body. Charles Darwin proposed the idea that because fish ovaries are considerably larger (30 to 70 percent of the female’s weight) than testes (5 to 12 percent of body weight), female fish invest more energy in reproduction than males.

Today, however, males get more credit. Because random spilling of sperm is a waste, males expend considerable energy to attracting females, establishing territories and running off trespassers.

Some male fish send out pheromones that cue a female to begin egg maturation. Others signal their fitness by turning bright colors or performing lively dances. And when the going gets tough, the tough change sex. Wrasses, parrotfish and anemonefish change sex as circumstances demand.

Studies show that larger female fish of all species produce more and bigger eggs, resulting in higher offspring survival.

That’s why it’s crucial in this era of depleted fish stocks to leave some of the biggest fish in the ocean.

Most people don’t associate Labor Day with reproduction like I do. But in nature, it’s the only labor that counts.


Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com

©2014 Susan Scott

Spanish dancer’s flare, eggs attract many devoted fans

Published July 8, 2013 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2013 Susan Scott

A rose is a rose is a rose — except when it’s the egg cluster of a Spanish dancer.

My recent column about that nudibranch and its roselike eggs generated some inspired email. About the lovely red or pink “flower,” a reader wrote, “I have seen the same thing and it looked like someone cut chiffon rosettes off an old-fashioned dress and glued them to the reef. I couldn’t figure out what in the heck they were. Now I know! Thank you.”

And thank you, Steph­a­nie, for describing so elegantly one of the world’s prettiest clutches of eggs.

Biologists call these flower look-alikes egg ribbons, and they are fastened with remarkable strength to the reef. The nudibranch might attach the eggs with a special glue, or the adhesive quality might be in the stickiness of the gelatinous egg cases. No one knows.

Also remarkable is the concentration of poison in the eggs, which contain more recycled sponge toxin than the nudibranch that laid them. In one lab experiment, researchers ground up the red eggs and fed them to creatures that eat almost anything.The offering were rejected.

Another Honolulu
reader, physician and photographer Russell Gilbert, wondered how the nudibranch
eggs held together, so he took a close-up picture. You can see the individual
eggs (and Russell’s other excellent underwater photos) here.

“After taking this shot,” he wrote, “I realized how the eggs were structured — embedded in sheets in some kind of gel-like material.”

He’s right. Multiple eggs are enclosed in rigid, protective mucus capsules, which stick to each other to form the spiraled ribbon.

Once hatched, free-swimming larvae drift in the plankton, eating tiny plants. When a baby dancer is ready to settle down, it alights on its food, one of several species of sponges.

Depending on which sponge species they’re eating, Spanish dancers are red, pink or orange, sometimes mixed with yellow or white.

Most nudies only crawl, but Spanish dancers get their common name from their ability to swim in midwater, flexing their bodies energetically, their soft edges flaring like the skirts of a flamenco dancer. Most people who see this flamboyant dance become lifetime fans and protectors of Spanish dancers.

Nudibranchs in general are not long-lived, some for only a month. The life span of dancers is about a year.

Occasionally, they beach. A San Francisco reader wondered by email whether returning a grounded one to the water revives them or if the creatures were trying to die.

I don’t know, but since nudibranchs have no eyes, my guess is that groundings are accidents occurring when the creatures get too near the shore break.

At the shoreline I once found a live Spanish dancer larger than my hand and waded, fully clothed, to place the creature on the ocean floor. I don’t know whether the orange beauty survived, but it was worth getting wet to give it a chance.

Spanish dancers and their eggs inspire most everyone who sees them. Maybe Elton John’s tiny dancer was a nudibranch, and Gertrude Stein’s rose its eggs.


Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com