Friday Spiderday with Cinnamon

cinnamon 3This has to be my favourite Belizean spider, the Cinnamon Tarantula (Crassicrus lamanai), first described in 1996 from specimens caught in New River Lagoon, Indian Church Village near the Lamanai Forest Reserve in Orange Walk District. Both the name of the reserve and the specific epithet are derived from the Mayan word lama’ anayin; this was the name of their ancient trading center, still standing centuries later, but now called Lamanai.

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This is a female as indicated by the cinnamon-coloured first three pairs of legs, and in the side view , the markedly incrassate (thickened) tibia of the fourth legs. Apparently the males are all black but I have yet to find one to photograph. This species lives in close association with the more common Mexican Red-rumped Tarantula (Brachypelma vagans), the two species completely sympatric and easy to find in communities of dozens of closely spaced burrows.

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On this shoot I actually caught both CLs and BVs with chewing gum! Usually, with a ball of chicle to hand (in Belize, the natural gum that comes from the Sapodilla, Manikara zapota) attached to fishing line, when teased the tarantula often sinks its fangs into the chicle and steadily one can draw them out of their burrow- in my case, all I had was the vastly inferior spearmint flavoured Chicklets (and yes, the brand name is derived from the natural substance) so it took a couple of hours and my last two packs of gum longer than it should have!

 

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The Mexican Red-rump Tarantula is completely sympatric with the Cinnamon, both species living in close proximity to eachother in mixed species communities.

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In Defense of the Moray

19858291626_2ce47bf8df_oThere has lately been another round of vilifying snakes, and more recently spiders, accusing them of everything from hunting down humans to original sin, when in fact from my experience the only spider I’ve ever had to be cautious about were the Brazilian wandering spiders in Peru that were happy enough to crawl into bed with you, and as for snakes, other than scares when not watching where you stepped on a trail, a rare occurrence of a Fer-de-Lance when riding in Belize that had just been disturbed by the horse in front.

This nonsensical scaremongering has just surfaced (resurfaced) concerning Moray Eels (Muraenidae; Anguilliformes), with a so-called “expert” aquarium vendor accusing them of being “poisonous” and causing harm to aquarium hobbyists with their “willingness to aggressively snap at your hand,” so let’s get this straight:

1. Moray eels would only be poisonous if you ate them, but actually eating them, other than large specimens that might have ciguatera, is not a problem- the accusation meant to say they were venomous, which of course they are not! (poisonous, you eat it; venomous, it “eats” you!);

2. Moray eels do possess a menacing appearance, with their mouths constantly agape but while an opened mouth display appears frightful, especially when coupled with pointed fangs, the eel’s physiology requires this behavior- its mouth must remain open to allow water to be pumped into the oral cavity, then over the gills by muscles located in the gill cavity and attached to the mandible or lower jawbone, the apparent “snapping” actually them gulping in water;

and 3. most moray eel species have limited vision and instead rely on a highly evolved sense of smell, so if you happen to be attempting to feed one and your fingers are too close, duh, that was you sticking your fingers where the eel was going for the food- this too is the only time I’ve ever seen a barracuda cause harm when a diver was feeding squid to a ray and left his fingers out in the fishy open when a small barracuda struck for the free food at 43 km/h! (no, they don’t chase you up the beach either!);

oh, and 4. stick your hand into a hole (including a confined space in an aquarium!), or step on the reef when diving/snorkeling, you’re asking for trouble as most fish don’t particularly like getting poked or trampled!

So here are a few of my favourite Morays, all photographed a mere few inches from the lens (patience and a non-threatening approach):

17216844478_dfa4e4814f_oYellow Moray (Gymnothorax prasinus); Bonaire, Dutch Caribbean

19703310230_3a46d4f207_oChain Moray (Echidna catenata), one of the “pebble-toothed” species; Bonaire, Dutch Caribbean

19942938446_b7e612efa4_oGoldentail Moray (Gymnothorax miliaris); Bonaire, Dutch Caribbean

19264399773_c66cb34216_oSpotted Moray (Gymnothorax moringa), Bonaire, Dutch Caribbean

19376467838_bc385eaed1_onot a Moray, but a Sharptail Snake-eel (Myrichthys breviceps), primarily a crab feeder which would explain its constant search, snake-like, through seagrass beds, and into crevices amongst the corals; Bonaire, Dutch Caribbean

Z is for Zygodactyl

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Today is the 26th and last day of the A-Z Photographic Glossary of Biological Terms challenge, so to finish the challenge it’s Z for Zygodactyl, as illustrated by this Keel-billed Toucan (Ramphastos sulfuratus),the National Bird of Belize, photographed by the Caves Branch River in Cayo District.

Zygodactyl (from Greek ζυγος, “even”) is an arrangement of digits in certain bird species and chameleons, with two toes facing forward (digits 2 and 3) and two toes facing back (digits 1 and 4). This arrangement is most common in arboreal bird species, particularly those that climb tree trunks or clamber through foliage, in particular parrots, woodpeckers, cuckoos, and some owls.

Y is for Yolk

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As a part of the A-Z Photographic Glossary of Biological Terms challenge, today it is Y for Yolk as illustrated by this frogspawn from a Vaillant’s frog (Lithobates vaillanti), a frog species found from Mexico through Belize and down to Panama.
 
We tend to think of an egg yolk as the yellow centre of chickens eggs, but one can be found in the eggs of all birds and most reptiles and insects, where the yolk takes the form of a special storage organ constructed in the reproductive tract of the mother. In many other animals, especially very small species such as some fishes and invertebrates, the yolk material is not in a special organ, but inside the ovum.
 
Yolks, being mainly stored food, tend to be very concentrated, and in particular tend to be rich in nutrients such as vitamins, minerals, lipids and proteins. The proteins function partly as food in their own right, and partly in controlling the storage and supply of the other nutrients. For example, in some species the amount of yolk in an egg cell affects the developmental processes that follow fertilization. Yolk is not living cell material like protoplasm, but largely passive material.
 
In frogs, the egg is composed of a series of jellylike layers that protect the developing embryo from desiccation, pathogens and, to a limited extent, predators. Surrounding the embryo is a structure called the vitelline membrane. Oxygen and carbon dioxide diffuse passively through this structure, enabling the developing frog to breathe; because of the lack of an outer shell, the egg must be deposited in the water or a very damp location to prevent drying out.
 
Frogs lay so many eggs because most, as in the Vaillant’s Frog, do not look after their young and so most will not survive to adulthood. From the several thousand eggs that one female lays, only around five (two tenths of one percent!) will become adult frogs. The rest of the eggs or tadpoles will be eaten by birds, fish, newts, water beetles, dragonflies or simply dry up before hatching.
 
In the photo above, the black dot is devoid of yolk but rich in cytoplasm and has the nucleus- this is known as the animal pole. Below, the unseen hemisphere of the egg contains the yolk which lacks pigment and is known as the vegetal pole. At the equatorial circumference will be found the place at which the male sperm will penetrate the egg, called the receptive cone. Once fertilized, each tadpole embryo will first eat the jelly that is around it until it is ready to hatch and shortly after hatching, the tadpole will then feed on the remaining yolk to get the nutritious start the tadpole will need prior to metamorphosis into adulthood.

X is for Xanthophyll

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As a part of the A-Z Photographic Glossary of Biological Terms challenge, today it is X for Xanthophyll, as illustrated by this Sassafras (Sassafrass albidum) photographed in the Autumn by the banks of Potomac River in Maryland in the eastern US.
 
Xanthophylls, from the Greek xanthos (ξανθός, “yellow”) and phyllon (φύλλον, “leaf”), are the typical yellow pigments of leaves. These are oxygenated carotenoids that are synthesized within the plastids. Xanthophylls do not require light for synthesis, so that xanthophylls are pretty much present in all leaves. The xanthophylls found in the bodies of animals are ultimately derived from plant sources in the diet; for example, the yellow color of chicken egg yolks comes from ingested xanthophylls.
 
Xanthophylls in leaves have an important function as accessory pigments, capturing certain wavelengths of sunlight not absorbed by chlorophylls, and thereby increasing overall absorptance of the visible spectrum of sunlight (absorptance is the ability of the leaf to absorb radiant energy.)
 
In the Northern Hemisphere, all the leaves on deciduous trees gradually lose chlorophyll during the growing season, and this loss accelerates just before leaf fall in the Autumn in non-tropical zones. Carotenoid pigments like the xanthophylls that were always present, yet masked by the volume of cholorophyll, are also lost during ageing but some of them are retained after the chlorophyll is lost producing yellow leaf colours.
 
Depending upon the continent, either the predominant Autumn colour is yellow- Europe and east Asia, or in North America it is red which is the result of the active synthesis of anthocyanin pigments just before the leaves fall; in these leaves the actual shades of red are the consequences of the acquired amounts of anthocyanin, the retention of carotenoids, and some retention of chlorophyll- predominant anthocyanin produce purples, anthocyanin and chlorophyll produce brownish colours, anthocyanins and xanthophylls produce orange hues as in the Sassafras above. In most trees and shrubs the color production is uniform, but in others, like the Red Maple below, we get leaves that are strikingly marked.
 
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For more on why the predominant colours in Europe and east Asia are yellow and oranges, but why in North America they are reds and purples- possibly the evolution of anti-herbivory defences, checkout this recent article.

W is for Wash Zone and Wrack Zone

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As a part of the A-Z Photographic Glossary of Biological Terms challenge, today we have two Ws for Wash Zone and Wrack Zone as illustrated by these Mangrove Periwinkles (Littoraria angulifera; Littorinidae) on the shores of the Sittee River Wildlife Reserve, Stann Creek District, Belize.

Both the wash zone and the wrack zones are adjacent to each other, the former the last zone of the foreshore, and the latter right at the delineation between foreshore and backshore, both found where the waves meet the beach.

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The wash zone is often also called the swash and is the turbulent layer of water that washes up on the beach after an incoming wave has broken. The swash action can move beach materials up and down the beach, which results in the cross-shore sediment exchange.

The wrack zone part of the shore is just above the mean high tide line where seaweed is deposited on the sand. This area is identified by the piles of seaweed and other debris like driftwood, and is often located on a slight shelf above the moist sand that slopes down toward the water.

The Mangrove Periwinkle a small marine gastropod that lives mainly above sea level on the branches and prop roots of the red mangrove, both in the wash and wrack zones of the Caribbean. It is ovoviviparous, where fertilized eggs are brooded inside the periwinkle and the veliger larvae are then released into the outgoing offshore flow (backwash) and become plankton; after about 9 weeks these develop into pediveliger larvae (with a foot) when they then undergo metamorphosis and settle.

Another marine gastropod that shares a similar habitat is the Four-toothed Nerite snail (Nerita versicolor; Neritidae), these ones found at Sanctuary Caye, Belize. This snail grazes on hard wet surfaces such as those in rocky intertidal zones, feeding on films composed of organic material and mineral particles, its only predator apparently various species of octopus; after prying the snail off of the rocks, the octopus runs the tip of an arm over the shell opening and operculum to determine whether the shell is inhabited and then will drill into the shell or pull the snail out through the aperture.

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V is for Vomeronasal Organ (VNO)

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As a part of the A-Z Photographic Glossary of Biological Terms challenge, today it is V for Vomeronasal Organ (VNO) as illustrated by this De Kay’s Snake or Northern Brown Snake (Storeria dekayi), native to the eastern US, Mexico, Guatemala, and Honduras, and although not recorded, one would expect it to also be found in Belize.

The vomeronasal organ (VNO), or the Jacobson’s organ, is an auxiliary olfactory sense organ that is found in many animals, including all snakes and lizards, plus many mammals.

Snakes use this organ to sense prey, sticking their tongue out to gather scents and then touching it to the opening of the organ when the tongue is retracted.

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Salamanders, like this Eastern Red-backed salamander (Plethodon cinereus) perform a nose-tapping behavior to activate their VNO.

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and certain species of freshwater turtles, such as the Yellow-bellied Slider (Trachemys scripta scripta) from the southern US, and the Twist-necked Turtle (Platemys platycephala) from the Manu region of Peru, use this organ to use their sense of smell underwater.

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The De Kay’s Snake is the only North American snake whose binomial is a double honorific: Storeria honors naturalist David Humphreys Storer (1804-1891), and dekayi is in honor of American zoologist James Ellsworth De Kay (1792–1851)

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