JIM CONRAD'S
NATURALIST NEWSLETTER
Issued in Río Lagartos, on the northern coast of
Yucatán, MÉXICO
in Ría Lagartos Biosphere Reserve

May 24, 2015

DOLPHINS AT SUNSET
Paco and I were returning late from a flamingo tour with a couple from British Colombia. The visitors had shown special interest in dusk's dramatic, stormy-looking, pre-rainy-season, low-slanting-sunlight-highlighted clouds, so Paco asked if they'd like to make a quick run through the canal in front of Río Lagartos to see the sun set over the Gulf of Mexico. It was spectacular, as you can see at http://www.backyardnature.net/n/15/150524dg.jpg.

The highlight of the moment, however, wasn't the sunset but rather the pod of feeding dolphins around us. Their top fins, or dorsals, alternately for two or three seconds would appear above the water, often followed by their rear, horizontally arranged flippers, or flukes, as they dove into deeper waters. Paco said it was normal at sunset at this time of year to see this.

Of course I tried to get a good picture, but it was all happening too fast. Only by pointing the camera at a busy spot and waiting for a fin to pop up could I get a picture, and with the low light and bobbing boat, the best I could do was what's shown at http://www.backyardnature.net/n/15/150524df.jpg.

Several dolphin species are possibly found in waters off Río Lagartos, and a fuzzy fin picture isn't much help in distinguishing them. The following dolphin species are listed for waters of the Gulf of Mexico off Río Lagartos:

Bottlenose Dolphins seem to be the most commonly reported, so maybe we were seeing them, but who knows? They all have top fins looking like what's in our photo, and horizontal flippers. Around forty species of dolphin worldwide are distributed throughout 17 genera.

You might be interested in a March, 2015 article in the New York Times entitled "Gulf of Mexico Turns Deadly for Dolphins."

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OCTOPUS IN A SEA-CUCUMBER GUT
During the current sea-cucumber season boats fishing several miles offshore normally are manned like this: One person is on the sea floor gathering up sea-cucumbers; another sits at the motor keeping the boat positioned properly, and; the third person hauls up sea-cucumbers in bags from below, cuts the animals across their bellies, and removes their stringy intestines -- which can be surprisingly long -- and throws them overboard.

Rayo, or Diego Jr., was handling the latter job when he cut open a sea-cucumber and found inside what's shown in his picture taken at sea with a cell phone, at http://www.backyardnature.net/n/15/150524oc.jpg.

It's a partially digested octopus, though it's too young for me to figure out which species it is. The main octopus occurring off our shores is the Mexican Four-eyed Octopus, our page for which is at http://www.backyardnature.net/mexnat/octopus.htm

The National Wildlife Federation says that sea-cucumbers feed on algae, aquatic invertebrates, and waste particles, so now we know that some of those aquatic invertebrates can be as large as a baby octopus.

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THE FLYSPECK CERITH
A couple from Iowa wanted to try the Maya Mud Bath, in which a certain mud the Maya use as a sunscreen and skin beautifier is smeared over the body, so at the end of the flamingo-viewing tour we pulled up to the mud bank, the Iowans went for their mud, and I was in the boat staring at the water.

The water next to the boat was about finger-length deep and the submerged mud was carpeted green with tongue-shaped Caulerpa prolifera alga, exactly as shown at http://www.backyardnature.net/n/15/150208cb.jpg.

Just to have something to do I slid my finger across the mud between the bases of the alga blades, until something interesting was felt, and retrieved. It was a living gastropod-type mollusk, small but pretty, only about 18mm long (2/3inch), shown at http://www.backyardnature.net/n/15/150524fd.jpg.

I took the time to look closely at the highly ornamented shell. Notice how it's organized into eight or nine major whorls, with each whorl bearing three rings of low "teeth," with the teeth lined up lengthwise. Between the teeth are irregularly appearing tiny brown specks. The shell's most elegant feature is the opening, or "aperture," inside which the mollusk has withdrawn its rubbery flesh. A close-up of the aperture is shown at http://www.backyardnature.net/n/15/150524fc.jpg.

Volunteer identifier Bea in Ontario came up with the name CERITHIUM MUSCARUM for the creature, sometimes known as the Flyspeck Cerith. The flyspecks are the tiny, brown spots between the shell's low teeth. Some shells display much more conspicuous and well ordered specks, but some shells show fewer. The Flyspeck Cerith is one of three Cerithium species listed for Ría Lagartos Biosphere. The species occurs from North Carolina south throughout the Gulf of Mexico and much of the Caribbean possibly as far south as Brazil. In Florida it's regarded as the most common Cerithium species.

Several crab species and a variety of gastropod mollusks are known to prey on Flyspeck Ceriths, and stingrays and horseshoe crabs are suspected as predators. Flyspecks are described as inhabiting shallow intertidal to subtidal zones, typically occurring in water less than leg deep, sometimes on naked mud but often in seagrass beds similar to where ours was found.

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LICHEN MANTIS
It's so hot and dry here, and has been so for so long, that I'm amazed anytime an insect appears that isn't feeding on nectar. Thus it was good to see the little mantis shown on a fallen tree limb at http://www.backyardnature.net/n/15/150524ln.jpg.

The curious feathery items at the rear of the abdomen are cerci, presumably used for smelling/tasting/feeling the environment.

This was a nervous, fast-moving little critter -- about an inch long, 25mm -- who with its good camouflage could disappear in a flash. Still, I managed to get a bit closer before losing him, as shown at http://www.backyardnature.net/n/15/150524lm.jpg.

Volunteer identifier Bea in Ontario pegged this as LITURGUSA MAYA, sometimes known as the Lichen Mantis, found from Mexico south through Central America to southern Peru.

The name led me to an online copy of a revision of the genus Liturgusa, which described species in the genus as "... bark dwelling species, which live entirely on the trunks and branches of trees and run extremely fast." The revision also made the point that the taxonomy of the species isn't well known, that Liturgusa maya is extremely variable, and that what's now called Liturgusa maya may well consist of a complex of "cryptic species," which are species so similar to one another that you don't know they're separate species until gene analysis is done.

Spotting this little mantid during such a hot, dry, relatively insect-less season brought forth a question: What on earth are they eating? There must be prey so tiny and invulnerable to drying out that I just don't see them.

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INSIDE AN ARBOREAL TERMITE NEST
Commonly seen in this area are bee-hive-size termite nests situated in trees. Our page showing and describing them them is at http://www.backyardnature.net/yucatan/termnest.htm.

This week I found an abandoned, broken-up nest with its insides visible, shown in a Jabim tree at http://www.backyardnature.net/n/15/150524tm.jpg.

Closer up you can see how the interior consists of many interconnecting chambers and tunnels, at http://www.backyardnature.net/n/15/150524tn.jpg.

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BUTTONWOOD MANGROVE FLOWERING
In our area, mangrove swamps are composed of four different species, and one of those is called Buttonwood. Our Buttonwood Page showing how most of the year it looks bear brown, spherical, pea-sized clusters of fruits is at http://www.backyardnature.net/yucatan/buttwood.htm.

Nowadays Buttonwoods are producing small, ball-shaped heads of unisexual and bisexual flowers arranged in panicle-type inflorescences. You can see clusters of male flowers at http://www.backyardnature.net/n/15/150524bw.jpg.

A close-up of a single head of male flowers bristling with anther-tipped stamens arising from densely crammed-together flowers is shown at http://www.backyardnature.net/n/15/150524bx.jpg.

Buttonwood flowers lack corollas, but their 5-sepaled calyxes look like green, hairy-bottomed corollas, as shown at http://www.backyardnature.net/n/15/150524by.jpg.

Bisexual flowers -- those with both functioning male and female parts -- also occur in spherical heads, but with fewer and shorter stamens, those heads aren't as fuzzy looking as those strictly composed of male flowers. You can see a ball of female flowers in which dark stigmas tip the single white styles arising atop each ovary, at http://www.backyardnature.net/n/15/150524bu.jpg.

Buttonwood flowers are "inferior," meaning that their sepals and stamens arise above their ovaries. A picture showing female flowers more developed than those in the above picture, with hairy-topped ovaries swelling and pressing against one another as the ball grows, is at http://www.backyardnature.net/n/15/150524bt.jpg.

Eventually the corollas are cast off and the squeezed-together ovaries turn brown as they mature into drupe-like (one-seeded) fruits, as shown at http://www.backyardnature.net/n/15/150524bs.jpg.

Later these brown, mature balls will harden, the individual ovaries will shrink and pull apart somewhat, and the ball will become crumbly, with individual fruits falling away.

Previously we looked at the pair of conspicuous glands on the Buttonwood leaf's petiole where it attaches to the blade. Historically those glands have been supposed to be salt-excretion glands, but now it's thought that they're just nectar glands that attract ants in a kind of symbiotic relationship. The gland situation isn't really well understood. This week while taking another look at the glands I noticed that many leaves also bear crater-shaped glands at the base of veins along the leaves' midribs, and even elsewhere on the blade's lower surface, as shown at http://www.backyardnature.net/n/15/150524bz.jpg.

A close-up of some glands is at http://www.backyardnature.net/n/15/150524bv.jpg.

Whatever service these glands provide for the Buttonwood, it must be important for them to be so prominent on the leaves.

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BRAZILETO FLOWERING
In thin soil in the savanna/ranchland zone southeast of town one of several woody species conspicuously flowering during this super dry, hot, end-of-dry-season period is the one shown at http://www.backyardnature.net/n/15/150524cg.jpg.

As with many trees during the late dry season, this species is leafless. However, in a picture showing its raceme-type inflorescence, you can see leaves beginning to emerge from buds in anticipation of rains due later this month at http://www.backyardnature.net/n/15/150524ca.jpg.

The raceme of yellow, fair-sized flowers suggests that this may be yet another senna-type tree -- a member of the Bean Family genus Senna or maybe Caesalpinia, of which several species occur here. The bilaterally symmetrical blossoms support that assumption. However, a closer look at the flowers reveals some surprises, shown at http://www.backyardnature.net/n/15/150524cb.jpg.

What's that darker, deeply fringed, scoop-shaped thing in which the stamens seem to be lying? And how about the wing-like items projecting horizontally above the stamens. I've never seen anything like this in either Senna or Caesalpinia.

A close-up look at a single flower's fringed scoop from below is shown at http://www.backyardnature.net/n/15/150524ce.jpg.

In that picture we see that the scoop is a sepal, or calyx lobe, and that the blossom's other sepals also are fringed, though not so deeply. Moreover, the sepals' "teeth" bear glands of the type that elsewhere we've seen attract insects by serving as a nutrient-rich food source, known as Beltian bodies. But those were on acacia leaflets, not a flower sepals, so this is quite something

Seeing all these unusual features, I began wondering if this might not even be a member of the Bean Family -- maybe something in the Milkwort or Suriana Family I hadn't heard of -- but then on other trees last season's fruit pods were found still hanging on, as shown at http://www.backyardnature.net/n/15/150524cd.jpg.

Those are classic Bean Family legume-type fruit-pods, and they even look like typical Senna or Caesalpinia fruits. Moreover, after scanning several completely leafless trees, finally one tree turned up issuing a small tuft of high-growing compound leaves, shown at http://www.backyardnature.net/n/15/150524cf.jpg.

Once again, Senna/Caesalpinia...

A good bit of sleuthing was required to figure out that this is CAESALPINIA MOLLIS, with no English name, but often known in Spanish as Brazileto, and in Maya as Chak Te'. Best I can see, it has a strange, discontinuous distribution, occurring only in the Yucatan Peninsula and in Venezuela and Colombia in northern South America. Little information is available on the Internet about it, and hardly any photos. Identification was possible only because a herbarium in Colombia presented some dried, mounted specimens online, filed under the name Brasilettia mollis.

This unusual species has been shifted from genus to genus, not only Caesalpinia and Brasilettia but also Coulteria. Other species with such fringed-glandular sepals are known in other parts of the world, so this is a definite "kind" of tree, just that so far the experts haven't settled on what genus they should be assigned to.

What a fascinating, mysterious species. And in our area it's fairly common, just prettily doing its thing, not worrying at all about its phylogenetic affiliations, or how it got split into two such widely separated populations.

*****

PICTOGRAM UPDATE
Last week we admired pictograms appearing on signs in Ría Lagartos Biosphere, but the messages conveyed by some of them seemed uncertain. That essay with several examples is at http://www.backyardnature.net/mexnat/no_nadar.htm.

Of all the pictograms, the most mysterious to me was the one shown on the right at http://www.backyardnature.net/n/15/150517sm.jpg.

Mark in the UK, Pam in Colorado and Diego here in Río Lagartos understood the message, which becomes apparent when you see that the "fins" are actually fingers of hands, and the hands are holding a pair of binocular shown in perspective, directed toward the raptor. Maybe the person who painted the flaring fingers hadn't known how to hold binoculars; also, each hand seems to bear five fingers and a thumb.

Bea in Ontario saw something even more interesting, in the "No swimming because of crocodiles" sign. That pictogram shows a swimmer being gulped down by a crocodile, but the crocodile inexplicably bore a crest atop its head, and something yellow was floating apart in the water, as shown at http://www.backyardnature.net/n/15/150524pj.jpg.

Bea added some yellow to the picture to create a less ambiguous pictogram, shown at http://www.backyardnature.net/n/15/150524pi.jpg.

It looks like the sign painter decided to improve on a standard symbol showing a swimmer by adding a line to create a crocodile's mouth, but the effect was marred by leaving inappropriate parts of the swimmer where they shouldn't be if the swimmer had been disappearing into the crocodile's belly. The artist had a fine inspiration, but didn't execute well.

So, that leaves only a couple of ambiguous pictograms -- the "Don't steal dirt" one and the "Don't pick the flowers" one, where the flowers look more like cat footprints. I'll let you know if anyone figures those out.

*****

THE BIG SEA-CUCUMBER PEPINEADA
On and off for the last three weeks a certain carnival atmosphere has reigned in Río Lagartos because of sea cucumber fishing season. In Spanish, sea cucumbers are called "pepinos de mar," and the event of their harvest is called the pepineada. Sea cucumbers are echinoderms like starfish and sea urchins. Our page on them is at http://www.backyardnature.net/yucatan/sea-cuc.htm.

People here don't care much for sea cucumbers as food, but in Asia they eat them and -- the kiss of death, as with rhinos, elephants and wild ginseng -- regard them as medicinal, even aphrodisiacal. The sea-cucumber business is big. Their harvest is regulated, with this year's quota for the Yucatan being 600 metric tons (661 US short tons). Many are taken illegally, despite the Mexican government's efforts at regulation.

My sympathies are with the sea cucumber. However, during these weeks I've witnessed features of the sea cucumber harvest that are worth documenting, if only because it's a traditional event destined to disappear in step with the disappearance of sea cucumbers.

When I jog along the Malecón each morning at 4AM, already the fishermen are out preparing their equipment and heading out to sea. Fishing grounds close to land already have been depleted of sea cucumber so now for a good catch they must go much farther out, into deeper, more dangerous water, so an early start is a good idea.

Normally each boat carries a crew of three. One person works on the sea floor breathing air through a hose attached to a special kind of mask coming from a small air compressor on the boat. He puts sea cucumbers into a bag, gives the bag's line a jerk, and the second man on top pulls it up. This second man also makes a slit on the bottom surface of each sea cucumber, guts it, and tosses the intestines overboard. The third man is at the boat motor, keeping the boat in place above the man on the bottom.

In mid afternoon, boats begin streaming back home through the canal in front of Río Lagartos. This Friday I was returning from a flamingo tour when I snapped a small part of the inflow, which continued for another couple of hours, shown at http://www.backyardnature.net/n/15/150524c6.jpg.

With big ice-coolers full of sea cucumbers, the boats head for their home fishing cooperative storage facility dock, where they line up side-by-side, waiting their turn to have their day's catch taken off and weighed, as shown at http://www.backyardnature.net/n/15/150524c1.jpg.

Each sea cucumber is quickly examined to assure that it's been properly gutted. Those that haven't been go into one container, while those properly cleaned are put into another. You can see a container being weighed at http://www.backyardnature.net/n/15/150524c2.jpg

The sea cucumbers then are dumped into large vats and boiled. Boiling softens them, facilitating the drying-out process. You can see vats of boiling sea cucumbers at http://www.backyardnature.net/n/15/150524c3.jpg.

Desiccation begins by packing layers of sea cucumbers with alternating layers of salt. In the above photo, white bags of salt are stacked against the wall in the background. After a day of drying in salt, the sea cucumbers are removed, boiled again, then repacked in salt again. Later they're dried more in the sun, as shown at http://www.backyardnature.net/n/15/150524c4.jpg.

In that picture the sea cucumbers already have shrunk dramatically in size. A fishermen leaning against a wall one afternoon outside the restaurant where I teach English told me that fully dried sea cucumbers are only about 1½ inches long (6cm). It takes 40-42 completely dried sea cucumbers to make a kilogram (15 per pound). In this dried-out state they're shipped to Asia, where they're re-hydrated, usually by micowaving them several times in water.

It's hard to believe the drama accompanying the pepineada. During the first week, about half the days were too windy to go out fishing, so fishermen hang around the second week hoping for permission to go out and make up their lost days. The permission was late in coming. One day the fishermen -- many from other towns, hugely swelling Río Lagartos's population -- decided to go out no matter what the government said. As I jogged at 4AM that morning, I heard a truck with a loudspeaker on it passing down the streets announcing that no permission was granted for that day, and that anyone who went out fishing would be treated as a pirate. Few if any fishermen went out that day. Big trucks loaded with ice sat with their cargoes melting, day after day.

This week, permission was granted and enormous numbers of sea cucumber were taken.

During these three weeks there's been robbery of sea cucumber catches, burnings of boats by fishermen jealous of their sea cucumber fishing grounds, deaths of fishermen suffering the bends as they came up from the ocean floor too fast, and all kinds of rumors. One day it seemed that most of Río Lagartos's population was gathered around a large, run-down tug newly towed up to a pier along the Malecón. People said the Navy had had a gun battle with "narco-sea-cucumber pirates" and confiscated their boat. The next day I heard that the body of one of the pirates had washed into the mangroves across from Río Lagartos. However, I can confirm none of this, though other details of the tension and violence along the coast are well documented in regional news outlets. All I know for sure is that for days the tug has been here guarded by men in uniforms, carrying automatic weapons.

To get a better feeling for what's going on here with regard to the sea cucumber season, you can check out the following, all freely available online:

ICSF.Net's article entitled "Mexico's sea cucumber fisheries management plan becomes effective."  

A 2014 article by CCTV-America.Com entitled "Underwater Hunt for Sea Cucumber Leads to Piracy, Smuggling & Black Market," at 

A 2014 article by World Academy of Sciences entitled "Science, diplomacy and sea cucumbers."

In Spanish, you can read current reports of fishermen dying from the bends, of boat burnings, robbery of sea cucumber catches, rampant rumors and tension, and military action along the coast, at the ProgresoHoy.Com site.

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FEATURED ESSAYS FROM THE PAST:

"Fat" from the October 24, 2005 Newsletter, at http://www.backyardnature.net/n/p/051024.htm

"Five Trainings for Mindfulness" from the July 6, 2007 Newsletter, at http://www.backyardnature.net/n/p/070706.htm

*****

Best wishes to all Newsletter readers,

Jim

All previous Newsletters are archived at http://www.backyardnature.net/n/.