SEA SERPENTS - A FISHY TALE
With the wind puffing her sails out full, the trading ship slipped threw the silent waters. Slowly the sun glided down to the horizon, casting eerie shadows over sea and ship. Standing alone at the port railing the captain gazed out over the deep blue watery surface. This was his fourth such voyage and though he had heard tales of sea monsters and serpents he had yet to see one.
Suddenly his hands gripped the polished wood until his knuckles turned white. Fearing the apparition would disappear he forced himself not to blink. For there it was just below the surface, the body extending down into the murky depths, the long silvery frame outlined by a red mane. The likes of which he had never seen before, one more story added to those already told.
The interesting thing about mythology, stories are frequently based on an event that occurred and expanded upon with the telling, or something which existed that was beyond the logic of the time and needed an explanation. Though old-time myths and legends may appear nothing more than fanciful stories, beware - truth of often stranger than fiction. Deep in the core of the inconceivable there might be a grain of reality.
Spiny-rayed fish, from the Phylum Chordata, account for about half of all species. Belonging to the class Osteichthyes, Subclass Actinopterygii, Superorder Acanthopterygii, they compose the largest fish group and evolved later than other fish species. There are a total of 15 Orders, 259 Families, and approximately 13,500 species.
Spiny-rays can be found in almost every sea and ocean environment. Generally having the supremacy of the inshore aquatic areas, and while they are numerous in lakes and ponds, they also inhabit open ocean areas and can be found in deep waters. Since they form such a huge group there is a varied array of shapes, colors, behavior, and adaptations to specialized environments, however, there are some anatomical similarities.
Most will have stiff, bony spines close to or right at the dorsal fin. This separates spiny-rays from the ray-finned fish, which have their fins held up by bone segments that are joined. Generally, the spiny-rays have ctenoid scales containing minute spines on the exterior of each scale. However, in some species the scales become bony plates, and there are species with no scales at all. Most spiny-rayed species have a movable mouth that can be extended forward, however, mouth shape and teeth types vary considerable.
Lionfish and stonefish fall into this group as well as tuna, plaica, sole, seahorses, bass, snappers, mackerel, and butterfly fish. Since the spiny-rays are such a varied group, it stands to reason there is a large size range, with the miniature gobies the smallest as 1 cm or 3/8 inches long.
And then you have the largest, the oarfish, Regalecus glesne, from the Order Lampridiformes, Family Regalecidae. The sea serpents measuring up to 8-ll meters or 26-36 feet in length. People have reported seeing specimens up to 17 meters or 55.8 feet long but this has not been confirmed, with the largest dependable record standing at 11 meters or 36 feet, and a weight of up to 270 kg or 600 pounds.
Recorded as the longest fish to be found in our waters, oarfish have a long, ribbon-like slender body that is only 5 cm or 2 inches across, it is also one of the most mysterious of our ocean dwellers. Oarfish are thought to be the source of stories incorporating sea serpents and ocean monsters. There are some who speculate the oarfish might be the origin of the Loch Ness monster, however, this has never been proven. As well as the sea serpent reputation, they were once believed to swim in front of herring shoals, as though guiding or leading them, hence they were crowned the 'king of the herrings'.
The habitat of the oarfish is worldwide. Being found in tropical, subtropical, and temperate areas of open seas and oceans up to a depth of 20-1,000 meters or 60-3,280 feet, including the Atlantic, Indian, Mediterranean, and the eastern Pacific from southern California to the south of Chile. Since these unique fish are seldom captured or even seen alive, our information comes mostly from specimens washed ashore, leading to a scarcity of knowledge about their lifestyle. It was not until 2001 that one was actually filmed in its natural element by the US navy. Their life span and current status is unknown, however, it is believed oarfisf are fairly common throughout their habitat.
Due to their unusual length they probably have few predators, however, the majority of oarfish that have been either seen or washed ashore had a part of their tail missing, or had scars along the rear section of their bodies. The internal organs of an oarfish are all contained in the front section of their bodies. They lack a swim bladder, however, there is an accessory digestive organ, a large bag connected to the stomach, extending back along the tail muscles to about the center of the body. Based on this evidence it appears oarfish can survive an attack as long as only the rear section of the body is bitten. It is theorized that the rear half could be completely bitten off and the fish would still survive.
Oarfish have no scales, however, the skin is covered with guanine, the substance that give fish their silvery color. Sloping, bluish-grey streaks are placed at irregular intervals along the length of its body. They have small eyes and a short, bluish concave head that slopes down in the direction of their protruding mouth. They have no teeth, however, they do have 40-58 long, spiny gill rakers used to filter small crustaceans such as euphausids contained in the water passing over their gills. For such large fish their food is fairly tiny, consisting of crustaceans such as krill, small fish, and squid.
Fins are a striking deep red with the dorsal fin, containing 260-410 rays, beginning at the front of the head and running the entire length of the body. The front rays of the dorsal fin are long, forming a high crest on top of the head just above the eyes. Pectoral fins are very small and located just behind the gills. The pelvic fins, situated just below the pectoral fins, consist of only two long single rays, one on each side of the body, ending in a tip resembling the blade of an oar, hence the name. Tail fins of oarfish are extremely small or missing altogether.
According to recent information, oarfish swim in the same manner as seahorses. Their bodies are held in a vertical position with the dorsal fin at the back. Small wavelike ripples running along the dorsal, combined with fanning movements from the pectoral fins, propel the fish slowly forward. The pelvic fins are held out to the side, acting as stabilizers.
Breeding habits are little known, except the oarfish is oviparous and their larvae, hatching from small eggs, can be seen floating on surface waters. Spawning is generally between July to December. The larvae have long streamers decorating with small pieces of skin. These streamers are part of the elongated rays from the frontal section of the dorsal fin and the extended pelvic fins, so far their purpose is unknown.
There are actually three species that go by the common name of oarfish. The Regalecidae family contains two genera. The genera Regalecus with two species, and the genera Agrostichthys with one species. Regalecus glesne, the oarfish discussed here, is the best known and by far the longest. The other two species are Regalecus russwlii and Agrostichthys parkeri, also known as streamer fish.
Oarfish are related to the Family Trachipteridae or ribbon fish. These fish are similar to the oarfish in body shape, however, they are shorter and fatter. There are a total of 16 species in the Trachipteridae Family, all rare with little known about their biology or life styles.
Trachipterus trachypterus measures up to 1.6 meters or 5-1/4 feet and can be found in the Mediterranean, Eastern Atlantic, Indian Ocean, and the Central and Western Pacific. Very similar to the oarfish, this ribbonfish as a small fan-shaped tail fin than slopes upward, with the deep red dorsal fin also running the length of the body. It has 1-4 dark spots widely spaced on the upper body and 1-2 on the underside.
Another relative, Trachipterus altivelis can sometimes be seen off the North American Pacific coast, in the region of the large salmon runs. Here, the coastal indigenous peoples had beliefs similar to the herring fisherman of Europe who called Regalecus glesne 'king of the herrings'. Believing that Trachipterus altivelis led the salmon migrations to the spawning waters, the indigenous nations bestowed this ribbonfish with the title 'king of the salmon'.
So....you still think there are no sea monsters or serpents. The next time you're sailing the seas take a look, perhaps you'll see that which you did not expect hiding beneath the surface. For who can say what lies in the dark mysterious depths in areas still waiting to be explored.
Photo from Wikimedia Commons http://en.wikipedia.org/wiki/File:King_of_herrings.png http://ias.pifsc.noaa.gov/lds/obs_training/Ribbonfish.pdf
MY NAME IS WHAT??????
What??????? This is ridicules! Absolutely ridicules! Slowworm?..... How dare you call me a slowworm? I'll have you know I can move very fast when necessary! And a worm? I have never wormed my way into anything!
I'll have you know that I'm very proud to be a member of the honored Class of Reptilia. Furthermore.... I'm a member of the important Order of Squamata. Furthermore..... my family is part of the royal Anguidae line with my genus and species being Anguis fragilis. Therefore, I am a lizard! Okay.... I might be a legless lizard but still a lizard nevertheless. I should add I'm related to the glass lizard, Ophisaurus attenuatus, of North America.
Ah.... I have your attention. So.... now you're curious and want to know a little about my species. All right, sit down on the flat boulders over there and pay attention.
First of all, our usual length is 30 cm (1 foot), putting us in the middle range where lizard size is concerned. However, a fine female slowworm holds the record at 52 cm (20-1/2 in). Sadly, I never had the pleasure of meeting her.
I know what you're thinking. Though I might look snakelike, I assure you.... I am not a snake. As do other lizards, I have eyelids that close and external ear openings. Inside our bodies we have rudimentary shoulder and hip foundations, proof that our ancestors once walked on four legs. Also, like other lizards the two halves of my lower jaw are jointed in front. Another difference between our species and snakes, snakes have forked tongues, now see..... when I open my mouth, the flickering tongue is notched.
As you see my skin is smooth with small round scales, which makes burrowing much easier, however, to my regret I have few markings and nothing fancy such as the monitor or Mexican beaded lizard. Which is upsetting..... Why? Don't you enjoy dressing-up and showing off your finery. Well.....?
See if you look closely, my back and flanks are almost the same color. However, we do come in different shades such as light or dark brown, gray, chestnut, bronze, or brick red. One variety is actually a nice copper color, and our underparts usually contain dark spots of black or dark gray.
Yes, you're correct, the females are slightly different. They will have a thin dark line down the center or their back and on the upper potion of their flanks, with their undeside usually black. What's that? You think my head looks strange? Well.... it is rather smallish and short. I guess with my body being broader than my head it does look peculiar. However, since I'm a male my head is longer than the females.
Oh, I mustn't forget a variety known as the blue-spotted slowworm, ummmmm how I hate that word. Anyways, they can be found in Europe and Southern England. I must admit they are beautiful with their coloring varying from a light blue to deep ultramarine. Now this coloring may be spots or very often stripes, which can be so close together they appear to be a solid blue. However, unfortunately only the males carry the blue markings.
What do we eat? I'm glad you asked that young man because this is very, very important. We prefer slow-moving invertebrates, including small slugs, earthworms, and snails. Since we help protect plants from the destruction that slugs, etc are known for, I'm delighted and more than a little pleased to say our culinary tastes lead to a warm welcome from gardeners.
Our personal life? Yes, I'll share a bit with you. Generally, we begin searching for suitable mates in April right through to August. Anywhere from 4-22 beautiful youngsters will appear after a gestation period of 90-100 days. Like many lizards, especially in cool climates, our females are ovoviviparous. Wow that was a bit word! It means our eggs are retained by the female, in thin membrane envelopes within the uterus until hatching time.
Our young, who are generally born in August or September, are just 7.5-9 cm. (3-3.5 inches), all having a black strip along the back and a black underside. Though, when born they do not have the coloring of their parents, we are very proud of our children. Right from the moment of birth they are active and able to take care of themselves. Capable of catching various insects our youngsters, like ourselves, prefer small slugs.
Where can we be found? Well, lets see, we cover a wide range throughout Europe, even Britain, Scotland, and Spain. Our population extends eastward to the Caucasus and even European Russia. Oh! In Sweden we extend as far as latitude 65 degrees north.
We have a very long life span of up to 55 years and dwell in a large variety of habitats. I must stress that we are completely harmless and since we feed largely on slugs, which destroy green vegetables, we are therefore very, very beneficial to humans and can easily co-exist. We enjoy open woodland and scrub, even cliffs by the sea and mountains. In heavily populated cities we can be found in hedgerows, orchards, and small gardens. We love wasteland and in England many of my relatives enjoy the peace and quiet of churchyards. Be we stay away from areas used for grazing or farming, also we avoid dense woodland.
We are fairly common, so far managing to avoid the sad misfortune of many other species. However, in some places our numbers are declining, such as in the United Kingdom where we are now listed as protected. Since we have a long list of predators, such as adders, frogs, birds of prey, foxes, etc, even though abundant we do take precautions. Meaning we are rarely seen, maintaining a secretive existence, most of the time hidden in leaf litter or in the soil. Can't be too careful these days. Our favorite meals, earthworms and tiny gray slugs, mostly show themselves at dawn and dusk so these are the times when we are most active.
However, I'll tell you a little secret. Sometimes during the day we do venture out, but only when the sun is shining. We don't enjoy wet, rainy days, something we have in common with humans. You see the warmth from the spring sun speeds up the development of the reproductive system and the females use the summer sun to help the growth of the embryos. Also by warming up we then have the energy to slither away very fast when danger threatens. Notice I said fast!
One of our favorite methods is to lie between two flat, thin stones on the ground. On sunny days the stones heat up right down to the underside, even when the sun isn't shinning some of the heat from the past day will remain. This way we can warm up our bodies without exposing ourselves to danger. We have discovered some types of human trash, such as corrugated iron sheeting, can be most effective.
However, I received an awful scare the other day. Here I was hanging out with several of my buddies under some sheeting, when suddenly a group of scientists picked up the sheet to count us. Of all things.... they had discovered the trick of placing flat pieces of metal on the ground to attract us. Can you imagine that.... of all the nerve.... disturbing a peaceful afternoon of warming up just to satisfy their curiosity. What is the world coming to?
Well, I see the sun is slowly setting and over in the next garden there are nice, juicy slugs calling. So I'll say goodbye, but please do not touch my tail as I slip away. Like most small lizards, when grabbed by a predator my tail muscles will contract, allowing the tail to drop off.
We have what you would call special breaking points within our tails just for this purpose. Actually it is is our major defense since the piece that has broken off will thrash about distracting our enemy, allowing us to escape. The muscles at the end of our bodies collapse, preventing blood loss and a new tail then grows, as good as the old one. It is due to this easy breaking of our tails that we came by our scientific name Anguis fragilis.
Now you're probably wondering does the tail always fall completely off. The answer is no. If part of the tail remains attached with the blood vessels intact, then the lizard could end up with a bifurcated tail and a new tail will also grow from the open wound. Meaning the lizard will be sporting two tails in the form of a V, with the bottom firmly attached to the body.
I'm afraid my time is up, my apologies but I must leave. However, if any of you wish to join me for my evening meal there are more than enough slugs to go around. Oh, too bad, I see none of you are interested in the invitation, then goodbye and please watch your footing.
Oh, before disappearing I have one more comment..... Slowworm!.... Bah! Humbug!
Photo from Wikimedia Commons by Jonas Bergsten
THE TUATARA OF NEW ZEALAND
The rustling of the overhead leaves warned the reptile of approaching danger. By the time the Pterosaurs flew overhead the little lizard-like creature was safely nestled in its burrow.
Two hundred twenty million years ago the surface of the planet earth was not as we find it today. The world was covered by water with only one exception, a large continent known as Pangaea. Over the next 50 million years Pangaea gradually split apart into various landmasses, however, it would be well over another 100 million years before the continents that we know today came into existence.
Pangaea was the birthplace of many different species, most of which have long since disappeared leaving behind only traces of their existence. One such species was the order of reptiles known as Rhynchocerphalians, with fossil records showing a worldwide distribution.
Then 100 million years ago, long before the dinosaurs became extinct, almost all of the Rhynchocerphalians vanished. All except the group that millions of years later came to be known as the Tuatara in the family Sphenodontidae.
Nicknamed ‘living fossils’ their external appearance is much the same as it was millions of years ago. Though they have undergone several evolutionary internal changes since the Mesozoic, such as adapting to colder temperatures.
They are the sole survivors of the ‘beak-heads’ that flourished 225-120 million years ago. Fossils, almost identical to the tuatara of today, have been dated back 170 million years.
Tuatara, which means peaks on the back, received their name from the New Zealand natives the Maori. Once widespread throughout New Zealand their population began dropping, roughly around 1,000 years ago, mainly from the impact of induced mammals brought by human explorers.
Today, the two remaining species of tuatara survive on approximately thirty-two islands, located in either Cook Strait, which separates New Zealand’s North and South Islands, or off the northeast coast of North Island. The species Sphenodon guntheri number around 400, while Sphenodon punctatus have numbers in the range of 60,000.
Most active at night they are a burrowing reptile preferring low coastal forests and shrub. It is not unusual to find them among colonies of burrow seabirds such as petrels and shearwaters. Though the tuataras are quite capable of digging their own homes they often prefer to share the seabirds’ burrows. Here the defecation of the birds and their activity on the floor of the forests help to produce the ground invertebrates that provides the tuatara with their food.
The tuataras are especially noted for their unusual long lifespan of well over one hundred years. Henry became the subject of worldwide attention in March 2008 when he mated for the first time at the age of 111 years with 80 year-old Mildred. In January 2009 there was immense jubilation when the eggs hatched producing 11 healthy hatchlings.
Resembling lizards in appearance they are nevertheless very different and have their own reptile classification in the Genus Sphenodon. Only two species, S. Punctatus and S. guntheri remain with S. diversum being extinct for well over one hundred years.
From snout to tip of tail the males measure 61cm/24 inches and weigh 1 kg/2.2 lbs, with the females slightly smaller at 45 cm/18inches, 0.5 kg/1.1 lb.
They have wide rounded heads with rather large eyes. The limbs of tuataras are powerful and clawed, well designed for defense and digging. A row of spines, (hence their name), extends down their backs and they are equipped with a stocky tail, which tapers down to a point. This tail, similar to some lizards, can be shed during an attack by a predator. Unlike most lizards, tuataras have no external ear openings, though they are capable of hearing.
Adults are olive-green, gray, or dark brown in color dotted with gray, yellow or white. Tuataras are egg layers with their clutch usually numbering 6-10 eggs, incubation lasts for roughly of 11-15 months.
Newly hatched youngsters are either brown or gray with shades of pink. Their heads are a pale color with a striped throat. They will occasionally have clearly defined light patches on body and tail.
Tuataras are of great scientific interest, not only as the last surviving species of the Order Rhynchocephalia and their long life span, but for several other unusual characteristics.
Tuataras have an unusual double row of teeth running along their upper jaw. These two rows form a perfect groove, which the teeth on the lower jaw fit into. These teeth are not imbedded in sockets, such as ours, but instead are fused to the jawbone forming a jagged edge, which wears down over time. Extremely old tuataras often have little or no teeth left.
One of the most unusual features is the presence of the “third eye”. Located just below the skin of the skull it includes a lens, a retina, and neural connections to the brain. Very little is known about this third eye. Theories suggest that instead of being image forming as in a regular eye, it is sensitive to light helping to prevent overexposure to the sun’s radiation.
These little creatures are rare, and their venerability might be partially due to the tuatara’s own reproduction cycle. Living in cool climates they have a very a low metabolic rate, leading to slow maturity and long life. Females do not reproduce every year. Instead there is an interval of 2-5 years between clutches. With an incubation time for the eggs ranging from 11-15 months, the longest for any reptile, the eggs are not guarded therefore putting them at risk.
The oval eggs with a flexible shell are laid in nests 20cm/8 inches deep with the sex of the offspring determined by temperature. Warm temperatures during incubation will produce males, cool temps results in females. After the eggs are in place, the nest is covered over and there is no additional parental care.
The youngsters use a horny egg-breaker, located on its snout, to slit the shell. Once free they dig their way to the surface and hide under stones or logs to escape predators. They will not reach sexual maturity until between the ages of 9 to 13 years, and will continue to grow until 20 to 34 years of age.
Completely protected by the New Zealand Wildlife Act many of the islands on which the tuataras reside can only be visited by permit. In 1990 the Tuatara Recovery Plan was set into motion, regulated by the New Zealand Department of Conservation and a Tuatara Recovery Group.
One method being used, in the Recovery Plan, entails the collection of wild eggs and raising the hatchings until they are old enough to be released. The youngsters are returned to the island and area from which the eggs were gathered. Or, reintroduced into viable habitats where the population disappeared or where the numbers are low, such as mainland New Zealand.
It’s due to this program that tuatara are once again thriving and breeding on the mainland. In October 2008 two nests, the result of reintroduced tuatara, were discovered at the Karori Wildlife Sanctuary in the capital of Wellington. The find was accidental, made during maintenance work by staff members. These nests were quickly covered over again and left undisturbed.
During March of 2009, workers spotted a young tuatara approximately one month old. This hatchling was the first to be seen on the Island of New Zealand in 200 years.
Proof that the ‘living fossils’ tuatara have returned to the land, where they had once roamed for millions of years.
Photo from Wikimedia Commons by Mark Whatmough