February 15, 2015
RED-BREASTED MERGANSERS
At low tide a mud bar barely above the estuary's waters was so loaded with Laughing Gulls it looked ready to sink. But one bird wasn't a Laughing Gull. Standing a bit apart, it was gawkily looking around like it'd just arrived, and maybe it had. It was a duck, but not a usual one. You can see it at https://www.backyardnature.net/n/15/150215mg.jpg.
With such a long, slender beak and the beginnings of a swooped-back head crest, it couldn't be anything but a merganser. But mergansers don't typically turn up here. The Yucatan Peninsula is way beyond their usual overwintering grounds, though sometimes a few winter vagrants do show up unexpectedly, so this is one of them, and no wonder the duck was so watchful.
Like most other overwintering birds here, this one's plumage was that of the immature or female, so there was the matter of figuring out which of the three North American merganser species this might be. For a split second our bird afforded a different view of its field marks by lifting its wings and stretching forward to take a poop, as shown at https://www.backyardnature.net/n/15/150215mh.jpg.
The Common Merganser was disqualified as a possibility because in that species the brownish head and upper neck make a more abrupt transition to the grayish lower neck than our bird shows. Also, Common Mergansers are more inland birds, and more restricted to the north. Of the three species, that's the least likely to occur here.
So, is it the Red-breasted or Hooded Merganser? The Hooded's bill is dark, not reddish, plus it is smaller and more slender than this bird's. This is the Red-breasted Merganser, MERGUS SERRATOR.
Red-breasted Mergansers dive and swim underwater. They mainly eat small fish, but also aquatic insects, crustaceans, and frogs. Our American birds nest from Alaska across Canada to Canada's eastern coast, and the contiguous US. The same species also occurs across northern Eurasia from Greenland and England to far eastern Russia, overwintering in places like Greece and the eastern coast of China.
With such a wide-ranging species maybe it's to be expected that a few individuals sometimes show up where they're not expected, gawkily looking around and taking a quick poop, before moving on.
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FORSTER'S TERNS
We're used to seeing dozens of Common Terns gathered thickly on mud bars barely emerging from the estuary's salty water, but that day there seemed to be terns of two kinds there, some paler than others. Studying them closer, other subtle, hard-to-put-into-words features could be recognized. It looked like we had two mingling tern species, but who was the newcomer? One on a post rising from the water was in its summer plumage, shown at https://www.backyardnature.net/n/15/150215ft.jpg.
Looking at distribution maps, and disqualifying all species these new birds could not be because of their field marks, soon it was clear that either the mystery birds were Roseate or Forster's Terns. In the end we just had to show the pictures to Diego, who assured us that they were Forster's Terns, STERNA FORSTERI. He pointed out that the Forster's Tern's legs are longer than those of other species, something the field guides don't mention. However, when pictures are compared on the Internet, this generalization turns out to be a good field mark. Also there are other subtler differences, such as the Forster's' paler primary feathers. Flying, the Forster's more deeply forked tail is distinctive, but that's hard to judge here.
Forster's Terns are winter visitors along the Yucatan coast, as they are the entire Gulf of Mexico Coast. They nest in south-central Canada and a bit of the north-central US. The vast majority of Forster's Terns on the mud flat that day were in juvenile plumage, but the one on the post in our picture, here in February, was in breeding plumage, and I don't know why. Forster's adults in winter normally have white head crowns.
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MANGROVE WARBLER
In the mangroves along the estuary's borders often we see Mangrove Warblers such as the one on a Black Mangrove stem shown at https://www.backyardnature.net/n/15/150215mw.jpg.
With a chestnut-colored head on a yellow body, this bird is easy to identify. True to its name, mainly it's found in mangrove swamps, though I've seen them in thorn forest a few miles inland.
The Mangrove Warbler is one of those birds that give taxonomists fits, because it doesn't fit neatly into human ideas of what a species should be. Some authorities list Mangrove Warblers as a distinct species but nowadays most consider them as mere geographic forms of the widespread and common Yellow Warbler. And even the Yellow Warbler's taxonomy has been debatable. Most of my life the species has been placed in the big genus Dendroica, but now most experts say it belongs in Setophaga, along with redstarts.
The Yellow Warbler is tremendously variable over its distribution. It nests throughout most of North America and winters from about here south into northern South America. Current thinking is that about 35 Yellow Warbler subspecies cluster into three main groupings. One of those three groupings, embracing about twelve of the 35 subspecies is referred to as the Mangrove Warbler, or erithachorides group. At this writing, the technical name of our Mangrove Warbler of the Yucatan is SETOPHAGA PETECHIA, ssp. BRYANTI.
Other than that and the fact that they display such outlandishly chestnut-colored heads, our Mangrove Warblers behave like regular warblers, hanging around in trees, especially trees beside bodies of water, and they like nothing better than to gulp down juicy caterpillars.
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GRAY SNAPPER
The road between Ría Lagartos and Las Coloradas crosses a narrow section of the estuary on a one-lane bridge. That bridge seems to be built for much heavier traffic than you'd expect on such a small road, until you meet barreling down the road one of many big, twin-trailer trucks that cross it filled with salt from Las Coloradas. Beneath the bridge there's a pier from which men toss nets into the estuary for fish. The other day I peeped into a fisherman's bucket and saw that it contained maybe ten smallish, yellow-lined Tomtate Grunts, and one silvery fish with a big mouth and ornamented with lines of small, dark, triangular specks along its sides. The friendly fisherman held up the fish for the picture at https://www.backyardnature.net/n/15/150215sn.jpg.
Even I could see the fish's sharp teeth. A close-up is shown at https://www.backyardnature.net/n/15/150215so.jpg.
When the fisherman set about filleting the Tomtates on a concrete block beside the pier, he seemed disgusted with his catch, remarking that he'd caught only one good fish that day, the one in our photograph, and even it was too small. The fisherman called this fish a Pargo. That's the name for what in English usually is called the Gray Snapper, or Mangrove Snapper. It's LUTJANUS GRISEUS, distributed from Massachusetts in the US and Bermuda southward to Rio de Janeiro, Brazil, including the Gulf of Mexico and Caribbean. Later I confirmed the fish's identity by counting its fin spines and such, though not many fish species have sharp front teeth like this one.
Gray Snappers feed mainly at night on small fish, shrimp, crabs, gastropods, cephalopods and other prey. They're regarded as good food fish, "Utilized fresh and frozen; eaten pan-fried, broiled, microwaved, and baked," as the FishBase.Org website says. An average size is about 1.3 ft (40cm), and ten pounders (4.5kg) are commonly caught along Florida's shores; they can grow to over twice that size. The species is known to reach spawning age at 7-13 inches (18-33cm), so our smallish one must just be reaching sexual maturity.
Gray Snappers, especially young ones, can tolerate varying degrees of freshwater and sometimes turn up in the lower reaches of rivers.
So far I've not seen a single fish of any species caught in the estuary that I'd regard as a good size, though quite a few large catches have been brought in from offshore, in the Gulf of Mexico. One reason for the estuary's small fish is that many ocean fish breed in the estuary and their young grow up here, often seeking shelter in the maze of mangrove roots and stems along the estuary's borders.
Another reason, which the fishermen themselves admit, is that this estuary is heavily overfished.
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CASE-BEARING LEAF BEETLE ON A THORN
On a Bull-horn Acacia's oversized thorn, a tiny bug about 3.5mm long (1/8in) caught my eye because he was black speck on a large, whitish thorn, plus he displayed a curious, dumpy shape bringing to mind a minuscule hippopotamus. Only beneath the hand lens were his unusual features apparent. You can see his goggly compound eyes, doglike snout, partial covering of white hairs and snazzy red side-patch at https://www.backyardnature.net/n/15/150215bt.jpg.
A shot from above displaying his blunt head and rear end is at https://www.backyardnature.net/n/15/150215bu.jpg.
With membranous wings folded beneath hard, black "elytra," which are modified front wings, obviously we had a beetle. But, beyond that, since about 375,000 beetle species are known and this was such a wee critter, what hope could we have of getting an identification, so that the creature's story could be learned? On the other hand, this was such an idiosyncratic-looking species that maybe there was hope. I shipped the picture off to volunteer identifier Bea in Ontario who after two days of her best sleuthing couldn't get anywhere. Later we realize that we both were erring in assuming that with such a long "snout" it was a kind of weevil.
Finally a website in Spanish dedicated to New World beetles was discovered, and with little hope of a reply I sent our picture to the site's producer asking for help. The letter went to a museum in the town of Curicó, Chile, and the entomologist Juan Enrique Barriga-Tuñón.
At his website, what a pleasure to glimpse the beetle-appreciating world at the museum, where over 600,000 specimens are mounted or preserved in alcohol -- and 300,000 awaite consideration. A page with evocative images of old-time naturalist deeply involved with what fascinates and charms them is at http://www.coleoptera-neotropical.org/8b-colecc-JEBC/JEBC.html.
Overnight Juan replied that we had a member of the Family Chrysomelidae, subfamily Cryptocephalinae, tribe Clytrini (Megalostomini), probably the genus Euryscopa or Coscinoptera. With this guidance, Bea came up with three possible IDs. After a lot of my own slogging through the literature, I'm fairly convinced that of her names fits our little beetle. It's COLEOROZENA PILATEI. Coleorozena pilatei is distributed from southern California, Nevada, Utah and Texas into southern Mexico, and typically associates with members of the Bean Family, such as the acacia on which our beetle was found.
Species like Coleorozena pilatei are too obscure to have common names. However, the Beetle Family to which the creature belongs, the Chrysomelidae with over 35,000 known species, is called the Leaf Beetle Family, and species in the subfamily to which it belongs, the Cryptocephalinae, with about 350 species in 22 genera, are referred to as Case-bearing Leaf Beetles. So, "Case-bearing Leaf Beetle" is about as close as we can come to an English name for our little discovery. Leaf beetles generally eat vegetative material.
Case-bearing Leaf Beetles get their name from the behavior of their larvae, which carry around cases of waste material. The case begins when the mother wraps plates of fecal material around each egg. When the larva hatches from the egg, it extends it head and legs from an opening, flips the case over its back and crawls away. As the larva grows, the case is enlarged with more of the larva's own waste. Eventually the larva pulls itself back into the much enlarged case, seals off the opening, and pupates inside. When the pupa metamorphose into an adult, the beetle abandons its case, feeds, mates, and the cycle starts all over again.
I still can't shake the feeling that our beetle looks like a weevil. The first thought is that it might represent a kind of evolutionary bridge between "normal" beetles and weevils. However, since Case-bearing Leaf Beetles and weevils belong to different "superfamilies," it's more likely the our beetle's similarity to weevils is a matter of "convergent evolution" -- fairly unrelated species evolving similar features because they are both evolving toward the optimum form for exploiting similar niches.
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APPLE MUREX SEASHELL
An interesting gastropod-type, sea-snail-sort of seashell had washed onto the Gulf of Mexico beach, more ornamented than most, as shown at https://www.backyardnature.net/n/15/150215ph.jpg.
Several kinds of shells more or less like this one wash onto our beaches but this one was distinctive because of the sides of its slender neck, which flare outwards into wavy wings. A shot from below provides another view at https://www.backyardnature.net/n/15/150215pi.jpg.
Volunteer identifier Bea in snowy Ontario quickly identified this as the Apple Murex, PHYLLONOTUS POMUM, a species whose shells on living beings are more colorful and more ornamented with warty ridges, wrinkles, concentric rings and such. You might enjoy seeing a variety of shells of this species at http://www.gastropods.com/6/Shell_1416.shtml.
Apple Murexes occupy shallow waters of the western Atlantic from North Carolina in the US south through the Gulf of Mexico and the Caribbean to northern Brazil. A website in Venezuela says that the local people there harvest Apple Murexes by diving. They eat the shells'contents and sell the prettier shells to tourists. Ours is a small one; in some places they grow to a height of five inches (13cm).
During low tides Apple Murexes bury themselves in the sand. If you happen to be on a beach exposed at low tide as the tide starts returning, they "pop from the sand," as beachwalkers like to say.
They make their living by drilling holes in oysters and eating the contents.
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BAY BARNACLE
On the east side of Río Lagartos a little pier extends into the estuary's waters and, as is normal for pier pilings, the pilings' bottoms are heavily encrusted with barnacles, as shown at https://www.backyardnature.net/n/15/150215bn.jpg.
A close-up showing a cluster of individual barnacles not over ¼-inch high (6mm) is at https://www.backyardnature.net/n/15/150215bo.jpg.
We've already admired the large, white barnacle species common on roots of the Red Mangrove along the estuary's sides, the Ivory Barnacle, AMPHIBALANUS EBURNEUS, shown at https://www.backyardnature.net/mexnat/barnacle.htm.
The barnacles on our pier pilings average much smaller than those and they're not as white. Add that to the information that I can find only three barnacle species listed as common along the Yucatan coast, and that one of those species is our big Ivory Barnacle, a second has conspicuously striated or lined platess unlike our piling species, and that the third species is a much smaller one not exceeding a height of ¼-inch... and one suspects that this is that third, smaller species, the Bay Barnacle, AMPHIBALANUS IMPROVISUS. This is a clumsy way to identify a barnacle, but since our pictures appear to match those of that species on the Internet and other printed details appear to sync, that's how we'll file them here.
Barnacles are crustaceans. All we see in our pictures are six rock-hard, fused plates forming a crater inside which two other plates close atop the crustacean creature lying protected inside the crater. The creature awaits the tide to raise waters to its level, so it can feed. When the water returns, the two plates inside the crater will crack open and six pairs of comb-like legs will extend into the surrounding water, rapidly waving back and forth, filtering from the water tiny plankton and other microscopic food particles that then will be brought into the crater, and eaten.
Bay Barnacles are found to a depth of about 20ft (6m) in temperate and tropical brackish and marine waters practically worldwide. They grow on a wide variety of surfaces, from rocks and shells of crabs and mollusks, and certain seaweeds, to ships, boats, harbor structures, and fishing gear. They're thought to be a native American species that has traveled to other parts of the world on and in ships.
As with Ivory Barnacles, Bay Barnacles are hermaphrodites who pass sperm between one another by way of long penises. Fertilized eggs hatch into larvae which drift out of the mother barnacle in water currents. After two to five weeks the larvae change into forms that move about until they find a suitable surface on which to settle, where they cement themselves to the substrate and metamorphose into juvenile barnacles.
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POMOL CHÉ
In thin soil atop limestone out in the zone where thorn forest mingles with savanna, a much-branched, thick-stemmed, chest-high shrub catches the eye with its completely leafless, swollen, semi-succulent stems, as shown at https://www.backyardnature.net/n/15/150215ja.jpg.
Even more eye-catching is that many of the grayish stems nowadays bear at their tips small tufts of tiny, delicate looking flowers, as shown at https://www.backyardnature.net/n/15/150215jb.jpg.
There you see male flowers consisting of purplish calyxes enveloping the corollas' bottoms, the corollas themselves with united lobes tinged with pink, and inside the corollas appear clusters of about ten pollen-producing stamens. I couldn't find female flowers, but it's early in the season and maybe later I can show them.
I've seen this combination of features before, especially the unisexual flowers and semisucculent stems, in members of the big Euphorbia or Poinsettia Family, the Euphorbiaceae. Therefore, it didn't take long to figure out that this fairly common shrub is JATROPHA GAUMERIA, endemic just to the Yucatan Peninsula south to northern Guatemala. It has no English and maybe no Spanish name, but the Maya are very aware of it, and call it Pomol Ché.
One reason for its fame aong among the Maya is that -- typical of juicy-stemmed members of the Euphorbia family -- the juice is full of powerful compounds that may be used traditionally as medicine.
In fact, the Maya know to drop Pomol Ché's sap, which is a transparent latex, onto ulcers or open sores, on the body or in the mouth, to promote healing. The latex is also used to clean gums and heal boils and fevers. Taken orally it's used for diarrhea and dysentery, by mixing its sap with that of the similar Jatropha curcas, which also occurs in our area. Children once used the light wood for making whistles, and its leaves were substituted for banana leaves when patting corn paste into tortillas.
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YUCATAN CAESALPINIA LOADED WITH FRUITS
Not long ago the Yucatan Caesalpinia, Caesalpinia yucatanensis, put on a show along our roadsides. Our page showing a typical tree and its pretty, yellow flowers spotted with red is at https://www.backyardnature.net/yucatan/caesgaum.htm.
Now later in the dry season the small trees have lost most of their leaves and flowers,while their naked branches now are sprouting small tufts of new leaves, and are heavy with legume-type fruits appropriate for the Bean Family the species belongs to. You can a cluster of flat legumes looking like large Lima Bean pods at https://www.backyardnature.net/n/15/150215cs.jpg.
A few branches still bear a blossom or two. You can see one, to help confirm the tree's identity, at https://www.backyardnature.net/n/15/150215ct.jpg.
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SALT-MARSH FLEABANE
There's a certain group of fair-sized, herbaceous members of the Composite or Sunflower Family whose curiously thick, urn-shaped heads lack petal-like ray flowers, and whose leaves always emit a powerfully musky-sweet odor when crushed, known by such names as camphorweed, stinkweed, sourbushes -- names referring to the leaves' pungent odor. They're members of the genus Pluchea, and over the years I've profiled several of them, usually in dry, often weedy habitats. Nowadays around here a certain Pluchea is loaded with pea-sized, purplish flowering heads, and the curious thing about the plants is that mainly they grow next to water that's often brackish or salty. You can see part of such a plant next to a little pond at https://www.backyardnature.net/n/15/150215pl.jpg.
A close-up of some flowering heads is at https://www.backyardnature.net/n/15/150215pm.jpg.
The plant's odor and the flowering heads' distinctive shape are so diagnostic for the genus Pluchea that this is one instance when it's not necessary to look at tiny details of individual florets and achenes to figure out the plant's identity. One nice feature about it is worth showing, however, and that's how the bracts forming the urn-shaped involucre holding the individual disc flowers, once the fruits are released into the wind, turn brown and curve backwards, forming interesting little brown "flowers," as shown at https://www.backyardnature.net/n/15/150215pn.jpg.
The genus Pluchea embraces 40-60 species of tropical and warm-temperate plants throughout most of the world, but only four Pluchea species are listed for the Yucatan. Our plant with its soft-hairy stems and leaves, entire leaf margin (lacking teeth or lobes), and preference for wet soil reveals itself as PLUCHEA ODORATA, and goes by such English names as Salt-marsh Fleabane, Sweetscent and Shrubby Camphorweed. It's native to coastal habitats and inland wetlands from the US south to northern South America, including the Caribbean, and it also turns up in western Africa and on certain Pacific Islands.
With such a strong odor you might guess that traditionally it's been used medicinally. In Mexico it's even honored with the appellation Santa María, a name applied to several unrelated but powerfully smelling herbs thought to be blessedly medicinal. Mainly it's used as a vaginal wash for various female problems, and for washing up after childbirth. Leaves and stems can be brewed with cinnamon sticks for a tea that alleviates menstrual problems. Teas also are used for upset stomachs, "rheumatism," fevers, to speed up deliveries during childbirth, and even for female sterility. Other uses include being taking for headaches, inflamed gums, lung ailments, earaches, and to cure such psychic or occult problems as "espanto," or fear, and "mal aire," which literally means bad air, when it's understood that witchery causes the air to be bad.
Moreover, a 2011 paper by S Bauer and others found that extracts of Salt-marsh Fleabane "disturb cancer cell cycle progression," thus warrent further study in the fight against cancer. A 2012 paper by M. Seelinger and others found support for the belief that extracts of the plant speed up healing and might hinder tumor formation.
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BITTER LETTUCE & ITS NAME
At the edge of the sidewalk beside the seawall along Río Lagartos's broad, pleasant-to-walk, peripheral avenue called the Malecón, there was a yellow-flowering weed that was so obviously one of the several ubiquitous and cosmopolitan "prickly lettuces" of the Composite or Sunflower Flower genus Lactuca, that the first few times I passed it by I didn't even tarry to give it a good look. However, eventually curiosity kicked in. Since here on the Yucatan's northern coast we have so many endemics and otherwise curious species, might not this plain-looking little plant actually be something interesting masquerading as something humdrum? I decided to "do the botany." You can see its "habitat picture" at https://www.backyardnature.net/n/15/150215lc.jpg.
Its flower head, consisting only of ray flowers, like a dandelion, was a typical prickly lettuce flower head, and a pleasure to contemplate against the Yucatan's deep blue sky, as shown at https://www.backyardnature.net/n/15/150215ld.jpg.
The ray flowers with their wishbone-shaped style arms spectacularly burst outward from their involucre, as seen in a top view at https://www.backyardnature.net/n/15/150215le.jpg.
Some of the plants heads already had matured, producing cypsela-type fruits topped with "white parachutes," their "pappi," designed for wind dispersal, as shown at https://www.backyardnature.net/n/15/150215lf.jpg.
The plant's Dandelion-like leaves cluster toward the base, but a few leaves do arise very low on the stems -- not all rising from the ground as with Dandelions -- as seen at https://www.backyardnature.net/n/15/150215lg.jpg.
When the plant was keyed out in the online Flora of North America, the key surprised me by not leading directly to the prickly-lettuce genus Lactuca. It said that the plant was a Launea, a genus I'd never heard of. Only one species of Launea is described in the Flora of North America, LAUNAEA INTYBACEA, and that species also is listed for the Yucatan. And that's what we have, an introduced weed from Africa, now invasive worldwide in tropical and subtropical disturbed areas such as roadsides and agricultural lands, but also in coastal strand vegetation. Sometimes it's called Bitter Lettuce, like several other species.
So, this ordinary weed was worth looking at, and it wasn't a regular prickly lettuce at all. But, the question arises, "Sharing so many features with prickly lettuce species, why isn't this also a prickly lettuce -- a member of the genus Lactuca?" When the matter was looked into, it became clear that over the years taxonomists have been uncertain as to how to deal with this species. In fact, even nowadays, about half the big, prestigious web sites dealing with plants do indeed regard it as a Lactuca. In the past the species has drifted not only between Launea and Lactuca, but also it's visited the sow-thistle genus Sonchus, as well as the murky genera Brachyramphus, Cicerbita and Phoenixopus. To me it's a Lactuca despite what Flora of North America says.
Anyway, Bitter Lettuce is a perennial that keeps producing new rosettes of leaves at the plant's bottom year after year, sending up new shoots from the root for several years, probably at the beginning of each new rainy season.
Lettuce found in salads is a member of the genus Lactuca and over the years we've feasted on several prickly lettuce species, so it's not surprising that Bitter Lettuce leaves are edible, though bitter. Green Deane at his EatTheWeeds.Com website says of it, "Don’t be surprised if you have to boil leaves 40 minutes or so in a lot of water to make it edible." Bitter Lettuce is also eaten by farm animals.
The name Launea intybacea struck me as a little exotic, so I looked up where it comes from. Probably the name Launea honors French botanist Jean Claude Michel Mordant de Launay, who lived from 1750-1816. He was a lawyer-turned-naturalist who as librarian at France's Museum of Natural History wrote books on gardening. The name intybacea is Latin for closely related and delicious Endive/Chicory, and that word came into Latin from the Egyptian word tybi, which means January, because that's the month when ancient Egyptians customarily ate Endive.
When you're walking along the Malecón with your mind wandering, wondering... there's just no telling where your thoughts will lead you.
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SHAVING BRUSH ALGA
When the tide is very low, as during our recent full-moon days, sometimes on flamingo-viewing trips you can reach over the boat's edge and pick interesting aquatic organisms off the estuary's floor. That's how I collected what's shown at https://www.backyardnature.net/n/15/150215pc.jpg.
This interesting being has been shaken briskly in the water to knock off the pale marl and general gunk that collects on sedentary things in the estuary's waters. From the boat when it was covered with marl, it looked more like an aquatic fuzz-ball lodged in an ocean of Shoalgrass blades, as shown at https://www.backyardnature.net/n/15/150215pd.jpg.
In my hand the thing felt a little stiff and crunchy, as often is the case with aquatics that become encrusted with calcium carbonate in carbonate-rich waters such as ours, or incorporate it into their bodies.
If last week I hadn't profiled the Mermaid's Fan, a member of the green alga family Udoteaceae, I wouldn't have had an idea of where to start trying the identification process. However, this week's discovery shares several features with the Mermaid's Fan and in fact belongs to the same family. By doing an image search on Google, on the keyword "Udoteaceae," and looking for algae with the general appearance of our find, it was easy to figure out that our alga is member of the genus Penicillus.
Four Penicillus species are listed for the Yucatan's waters, of which only one is described as inhabiting lagoons such as Ría Lagartos Estuary -- the others being marine. And that one lagoon-loving species is also the one looking most like ours, with its egg-shaped bushiness atop a long, slender stem. Our alga is called the Shaving Brush Alga, PENICILLUS CAPITATUS, and it's described as among the most common and conspicuous shallow water macroalgae in the Caribbean region.
Shaving Brush Alga is "coenocytic," which means that instead of being composed of cells with walls, the organism's many nuclei, photosynthesizing chloroplasts and other organelles remain loose within its body's cytoplasm. In fact, the whole body may be considered one gigantic cell. This is a characteristic condition of the whole green alga order known as the Bryopsidales, to which Shaving Brush Alga belongs, so it's not just peculiar to this one species.
Shaving Brush Alga mostly reproduces vegetatively, through fragmentation, but under special conditions the contents of the whole organism transform into untold numbers of sexual gametes, which are released into the water, have sex, and produce new Shaving Brush Algae. This mode of sexual reproduction is known as "holocarpy." A study in the waters of St. Croix found that Shaving Brush Algae lived from between one and 16 weeks, with most individuals surviving eight weeks or longer.
Shaving Brush Alga grows in shallow, warm bays and lagoons, where it may form large colonies or be mixed with sea grasses, as in our case. It's distributed from southern Florida and the Bahamas through the Caribbean.
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CROWS UNDERSTAND ANALOGIES
Eric in Mérida sends a link to an online, freely accessible article in Scientific American entitled "Crows Understand Analogies." It supports the notion that animals besides humans entertain complex insights. The link is http://www.scientificamerican.com/article/crows-understand-analogies/.
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FEATURED ESSAYS FROM THE PAST:
"Education --> ... " from the July 26, 2009 Newsletter, at https://www.backyardnature.net/n/p/090726.htm
"Revolution, Education & Sustainability" from the October 22, 2007 Newsletter, at https://www.backyardnature.net/n/p/071022.htm
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Best wishes to all Newsletter readers,
Jim
All previous Newsletters are archived at https://www.backyardnature.net/n/.
