Now, I will try to show part of his work to Italian Tortoises breeders, hoping it will provoke some interest, comments and notices in future fruitfull discussion. Also, all remarks will be of high value, due work in Burmese Stars (as well in Indian Stars and Radiated Tortoises) is still in the beginning…
1. GENERAL MORPHOLOGY
Before starting to describe their morphology, first we have to compare them with other common turtle and know their unique character.
The CARAPACE of common Turtles has four kinds of scutes (1 nuchal, bilateral 12 marginals, bilateral 4 pleurals & 5 vertebrals) [Photo 1].
We can see the Burmese Star has no nuchal scute, and there are only 11 marginal scutes on each side; the supracaudal scute is not divided [Photo 2]. The carapace of Burmese Star is oval, domed and generally flattened without pyramiding.
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The PLASTRON of common turtles has 10 kinds of scutes (intergular, gular, humeral, marginal, axillary, pectoral, abdominal, inguinal, femoral and anal) [Photo 3]. The plastron of Burmese Star has no intergular scute [Photo 4].
And their plastron formula is : abd > hum > fem > gul > an > pect;
the pectoral scute is extremely narrow.
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As to the head SCALE, there is a large prefrontal scale divided longitudinally and followed by a large single frontal scale; other head scales are always small [Photo 5].
The forelimb is covered with large pointed to round scales [Photo 6 ].
The tail is ended with a large horny scale [Photo 7 ].
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There are several differences between the MALE and FEMALE in Burmese Stars. The male is more elongated in shape; his plastron is concave and has a longer, thicker tail [Photo 8 & 9].
It’s very strange that male population is only half as the female in the Chinese food markets (as well in Thai Pet Shops). Maybe it’s due to high nature incubation temperature in Burma or higher mortality of males in the wilds!?
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2. SCUTE PATTERN
This is the main part important to show to the tortoise lovers. The Burmese Star has very unique scute markings compared to other species. The simplicity of their stripe pattern make this species a good subject to learn about the variations, classifications and heredity of the tortoise. Let me introduce it now:
A. CARAPAX
Their CARAPAX is dark brown or black with six or fewer radiating stripes extending from the yellow areola of each vertebral and pleural. There are two yellow stripes forming a V-shaped pattern on each marginal scute.
To describe the scute stripes pattern of Burmese Star, first we have to point out the angle lines of scute annuli [Photo 11]. Angle lines of scute annuli appear in all kinds of tortoises species, which are false lines formed from the scute angle of yearly growth annuli. It’s very interesting that scute stripes of Burmese Star happen to lie strictly on the angle lines. Burmese Star is the only species that follows such rule. We can’t find such characters from other star tortoises. It’s astonishing to find such unique striae pattern in tortoises.
Just tracking the angle lines, you can sketch a standard scute stria pattern of Burmese Star [Photo 12]. Followings are those detail discussions.
The common arrangement of their CARAPAX STRIAS are :
Vertebrals = 5-6-6-6-6 (from 1st to 5th); pleurals = 7-6-7-5 (from 1st to 4th); marginals = 2 in V-shape [Photo 13]. But when we inspect more specimens, we find there are several unique group varieties in stria pattern which might be due to genetic heredity. The varieties are:
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The 1st vertebral scute:
Photo 14 : 1st vertebral scute (4 stripes)
Photo 15 : 1st vertebral scute (4 stripes plus 1 slender stripe)
Photo 16 : 1st vertebral scute (5 broad stripes )
Photo 17 : 1st vertebral scute (4 broad plus radiated stripes)
Some has only 4 stripes; some owns 4 broad plus 1 slender stripes; some contains 5 broad stripes. Their distribution ratio in Dr. Liu’s colony is = 40% : 45% : 11% :4%. So the majorities have only 4 , or 4 plus a small protruding stripes on their 1st vertebral scute.
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The pleural scute stria:
Photo 18 : Common pleural scute (stria code: 7-6-7-5)
Photo 19: Common pleural scute of a true specimen (stria code: 2/5-3/3-3/4-2/3)
Photo 20: Another pleural scute (stria code: 7-6-7-6)
Photo 21: Another pleural scuate (stria code: 8-6-7-6)
They always follow the strict code: 7-6-7-5 (from 1st to 4th pleural scute) with an interesting arrangement of 2/5 (2 up, 5 down) “V 3/3 “V 2/5 “V 2/3, and the 6th marginal scute has 3 stripes (W -shape, instead of V - shape) [Photo 18 & 19]. Of course, there is a variation: some have the code of 7-6-7-6 , which have an extra-stripe on the 4th pleural scute, and if it appears, the 11th marginal scute will have 3 stripes (W - shape) [Photo 20]; some have the code of 8-6-7-6, which have an extra-stripe on 1st & 4th pleural scutes, and by then, the 5th & 11th marginal scutes will have 3 stripes (W - shape) [Photo 21].
The ratio of these three groups in Mr. Liu colony is = 70% : 17% : 13% .
The majorities follow the code of 7-6-7-5.
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The rear carapace scute stria:
Photo 22: Rear carapace scute stria (Slender type; without fan)
Photo 23: Rear carapace scute stria (Intermediate type; with thin split fan)
Photo 24: Rear carapace scute stria (Broad type; with coarse split fan)
Photo 25: Rear carapace scute stria (Fan type; with coarse fused fan)
We find four basic types of scute stria. They are :
1. Thin stria without fan (the Slender type; Photo 22)
2. Coarse stria with thin split-fan (extra thin split-fan stria over the 4th & 5th vertebral scute; the Intermediate type; Photo 23)
3. Coarse stria with broad split-fan (extra broad split-fan stria over 4th & 5th vertebral scute; the Broad type; Photo 24)
4. Coarse stria with double fans (extra fused fan stria over 4th & 5th vertebral scute and extra split stria over bilateral pleural & supracaudal scute; the Fan type; Photo 25)
Their ratio in Mr. Liu’s collectio is = 43% : 30% : 14% : 13%.
There are only very a few beautiful double fan specimens; mostly are males.
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B.PLASTRON
Photo 26 : plastron without radiated stria (Blank type)
Photo 27 : plastron with scarce radiated stria (Scarce type)
Photo 28 : plastron with webbed radiated stria (Web type)
Photo 29 : plastron with blotchy stria (Blotch type)
The plastron is covered with yellow ground color, and plastral scutes have a broad black patch with or without radiated stripes in between.
The ratio of these 4 groups in Dr. Liu’s colony is = 43% : 30% : 17% : 10%.
So the Blotch type are scarcely seen, and most of them are Blank type.
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3. CLASSIFICATION
Photo 30: Whole view of N group (Slender stria group; L: male, R: female)
Photo 31: Whole view of S group ( Intermediate stria group; L: male, R: female)
Photo 32: Whole view of F group ( Broad stria group; L: male, R: female )
Photo 33: Comparison of three groups (L to R : N – S - F group, males)
Photo 34: Comparison of three groups (L to R : N – S - F group, females)
Photo 35: N group colony
Photo 36: S group colony
Photo 37: F group colony
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Dr. Liu basically classified them into three groups by the thickness of their carapace scute stria. They can be easily divided by three types from the slender, intermediate, and broad stria of their rear carapace stripes [Photo 22 to 25].
These three groups are :
1. N group: Slender stria with non-fan shape stripes on 4th & 5th vertebral scutes. Their stripes are always in pale white color and less expansion at end [Photos 30 & 35].
2. S group: Intermediate stria with split-fan shape stripes on the 4th & 5th vertebral scutes [Photos 31 & 36].
3. F group: Broad stria with double-fan shape stripes on the 4th & 5th vertebral scutes. Their stripes color are always orange yellow and much wider expansion at end [Photo 32 & 37].
The ratio of these three group in Dr. Liu’s colony is = 40% : 33% : 27% (N : S : F). The S group dominates the majority.
In males, the group ratio is = 20% : 40% : 40% (N : S : F).
In females, the group ratio is = 50% : 30% : 20% (N : S : F).
We can see that most of the males are F group, and it”s very hard to find a typical N group male. But in females , the ratio reverses.
N group occupies the majority and a typical F group female is also not easy to find in the Chinese and Thai markets. Why does there exist such different distribution? Are the N group males and the F group females hard to survive in the wild? Dr. Liu is thinking his colony ratio might be a valuable data because all his specimens were collected by random from food markets. It may represent the wild populations in some degree. But it may not be true, just a bias of his collection. A true population data needs a great deal of long term field survey.
The stria varieties may be due to different geographic distribution. It is said that the specimens with slender stripes (N group) are found near the border area between northern Burma and Yunnan Province of mainland China; and the specimens with broad stripes (F group) are always found in southern Burma.
The breeders appreciate the F group males and N group females. Their unique scute markings are the true beauty “Star Tortoises”. But, the individual varieties which can be divided into groups are not just for Burmese Star; other species also own the characters. The Indian Star and Radiated tortoise can be grouped in the same way, if we want to do it. As we know, the species which have been grouped by outlooks are G. elegans, G. radiata, G. pardalis and G. carbonaria (If you visit the web site of Dr. William Zovickian - www.tortoiseman.com, you will see his radiated tortoises are all distinct with beautiful broad stripes, which are specially selected to breed from a large colony. As to G. elegans, tortoise keepers have already divided them into Indian Stars (thin striped) and Sri Lankan Stars (broad striped). G. pardalis now have been purposely divided into several groups from snow white to dark black, as we tried to clear inside of previous discussion….
As to G. carbonaria, as we know well, two kinds of them have shown by the breeders: common Red-Footed Tortoise & Dwarf Red-Footed Tortoise (Cherry-headed). If we have the opportunity to inspect a large colony of a same species, we may have the chance to divide them into different groups. It’s very interesting and meaningful to classify them. It may become a pioneer study of tortoise heredity. I believe someday the tortoises can show its natural or man-made varieties just as Corn Snakes in our pet markets, although it will have to take a great deal of time!
4.PYRAMIDING
Photo 38 : A specimen with pyramidal carapace
Photo 39 : Comparison between normal & pyramid specimens
Photo 40 : Pyramid group
From the common name of Burmese Star, i.e. “Flatback Tortoise”, we can see that generally its carapace should be flat without pyramidal formation. But it’s not always the case. Dr. Liu obtained his first pyramid specimen from food market (wild catched specimen!!!). Her carapace pyramidal formation became more obvious during two years’captivity [Photo 38]. You may suspect that it’s a result of metabolic bone disease. But Dr. Liu doesn’t think so. [Photo 39] shows two specimens kept under the very same diet & environment, but they came out to be different. Later, Dr. Liu obtained another few pyramid specimens [Photo 40]. They all have the same characters of initial slight elevated carapace and rapid growth rate. They are a rare part of his colony (only 13%). It might be a result of hereditary variety. Anyway, I am still considering Burmese Stars as FLAT Tortoises; independing, there are some specimens with pyramids just as Indian Stars & Radiated Tortoises!
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5. “STAR” TORTOISES COMPARISON
Photo 43: Different carapace scute stripes representing four “Star” Tortoises (Burmese, Radiate, Indian, Sri Lankan Star).
Photo 44: Outlook comparison of Sri Lanka star, Indian Star, Burmese Star, & Radiated T.(from upper to lower)
Photo 45: Plastron comparison of Indian star, Radiated T. & Burmese Star. (from left to right)
The Burmese Star has unique symmetric 6 or 5 scute stripes; Radiated Tortoise has sharp longitudinally radiated stria pattern ; the Indian Star has more numerous, thinner & orange-yellow stripes ; but the Sri Lanka Star has less numerous, broader, pale yellow stripes. We can see all the differences from [Photo 44].
The Burmese Star originally are thought to be a subtype of G. elegans. But if we compare these three species from plastron [Photo 45], you can see that Burmese Star has the very similar scute markings as Radiated T. So we should believe (!?), from the scute markings of carapace & plastron, Burmese Star is much more related to Radiated Tortoise instead of Indian Star.
But how can we explain the large distance of geographic distribution???? It may just have the same historical background as the Aldabra Tortoise and Galapagos Tortoises????
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9. CHARACTER
The temperament and activity of Burmese Star is almost in the intermediate place between G. elegans and G. sulcata. They are not so shy as Indian Star; yet much active, alive as G. sulcata. But they are smarter than G. sulcata. They are very responsive, always turning their heads staring at you to conjecture of your doings. Besides being a little over-paniced when being touched unexpectedly, raising them is truly a pleasure!
Wishing all the best in all Turtles/Tortoises breeders during the next 2007. season,
Yours truly, Marco
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