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Introduction

This article covers the basic care of Coelognathus flavolineatus in captivity with sections on Taxonomy, Etymology, Scutellation counts, Natural History, Locales, Behavioural Traits, Captive History & Care, Temperature, Humidity, Water, Substrate, Cage Furnishings, Breeding, Cycling, Copulation, Gestation, Egg Laying, Incubation & Rearing Hatchlings.

  Yellow Striped RatsnakeAn Introduction To The Yellow Striped Ratsnake
Coelognathus flavolineatus (Schlegel, 1837)

Etymology
Coelognathus :
Greek: Coelo meaning Hollow
Greek: gnathos meaning Jaw
flavolineatus :
Latin: flavius meaning Yellow
Latin: lineatus meaning Lined

Scutellation Counts
Ventrals: 198-242
Subcaudals: 80-116
Supralabials: 8-9
Infralabials: 10-11

TAXONOMY

In 2001 studies by Notker Helfenberger split this species along with The Radiated Ratsnake (C.radiatus), Trinket Snake (C. helena), Philippines Ratsnake (C. erythrurus) and Timor Ratsnake (C. subradiatus) from the Elaphe (Fitzinger 1843) genus and revalidated the genus Coelognathus for these species. This name had previously been used by Fitzinger in 1843 for radiatus.

The Yellow Striped Ratsnake, is one of several common names used to describe this species, Common Malayan Racer, Copperhead Racer and Blacktail Racer are amongst others and ones that have also been used to describe other Asiatic Ratsnake sp. which is why in my opinion it is better to refer to species by there scientific name so as not to cause any uncertainty.

Carl Linnaeus (a Swedish biologist) decided in 1758 that everybody should use the same names to describe the same species and proposed a universal naming method. This naming system is known as "binomial nomenclature" (bi = two, nomen = name, calo = call, translated as "two-name name-calling"). Each species has a 'surname' and a 'personal name' just like we do. If you are called Joe Public then Public is your surname, and Joe is your personal name.

Scientists call the surname the "generic name" or "genus" and it always has a capital letter as the first letter. The personal name is called the "specific name" and is always written in lower case. Unlike our names the surname (generic name) comes first followed by the personal (specific) name. For instance the Latin name for The Yellow Striped Ratsnake is Coelognathus flavolineatus (as a rule we either write it in italics or underline the scientific name so that you know that it is a species name). Coelognathus is the family name, and there are at least another 4 species that have the same family name (just like brothers and sisters would have the same surname).The specific name flavolineatus is like your first name.

Further more the scientific names always means something, they either describe the plant or animal or tell you who first gave the species that name.

The name and date in brackets after a species name (Coelognathus flavolineatus (Schlegel, 1837) tells us who first described the species and in what year.


NATURAL HISTORY

Coelognathus flavolineatus is to be found on the Indonesian islands including Java, Sumatra and Borneo, the Indian Islands of Andaman and Nicobar and mainland Western Malaysia and in the south of Thailand and Vietnam.

C. flavolineatus is a tropical species that inhabits a variety of biotypes from sea level up to 900m although most often found in scrub areas on the edges of rainforest concealed away under forest floor debris such as coconut shells and brushwood. It is not unusual for them to be found near human settlements where they will enter homes in search of mice and rats.

They are a medium sized quite slender snake reaching lengths of up to 200cm, agile, strong, fast and somewhat aggressive.

In the wild adults eat a variety of prey items including rats, mice, bats and birds. In the book Fascinating snakes of Southeast Asia (Lee & Lim), they have recorded instances of juveniles feeding on Lizards & Frogs as well as young rodents.

  Indonesian Yellow Striped ratsnakeLOCALES

The appearance of C. flavolineatus is quiet varied and depends mostly on where they come from.

Most of the specimens we have seen in the hobby in the past have been a dull brown – olive colour gradually getting darker past the 100th ventral scale with the tail being black, the yellow stripe is only faintly visible. Not a very attractive snake and one that has not been high on Ratsnake enthusiasts wanted list in the past.

Mainland forms are one of the most attractive with there bright, colourful appearance as hatchlings remaining with them throughout adulthood. Those from Vietnam, a recently discovered locale for this species being the brightest and most sought after in captivity with a golden yellow stripe edged with black, clean white & black chin markings and a raven coloured tail.

Javanese specimens fade out as they mature and the yellow stripe is less noticeable. The Sumatra population are brilliant yellow for the first third of there body and the stripe is very faintly visible, fading out to black at the tail giving a striking contrast.

BEHAVIOURAL TRAITS

Schulz in his book A Monograph of the Colubrid Snakes of the Genus Elaphe Fitzinger, remarks on them having a threat display similar to that of the Radiated Ratsnake where they inflate their throat, ‘S’ up and gape there mouth. I haven’t witnessed this behaviour in mine, only a slight inflation of the throat when feeling threatened. They are a very alert species and watch you from the entrance to their hide when ever you’re in the room, head lifted off the floor, they don’t seem to take there eyes off you. If you enter their cage they will retreat back into their hide, disturbance causes them to flee past you. They are a difficult snake to handle, strong and always active, if you should try and secure them by holding them behind the head they go into a death roll, twisting violently until you release them. They also have a tendency to musk when handled which smells quiet pungent and sweet. Captive bred and raised specimens may be more tolerant of handling, as is the case with other species of this genus, who are equally if not more aggressive as Wild Captives.

CAPTIVE HISTORY

Wild caught Yellow Striped Ratsnakes are infrequently imported into the hobby, perhaps a few specimens each year into the UK. Many of these do not do well; in the past arriving dehydrated, stressed & parasite ridden they were certain to die within a very short time in captivity either due to their poor physical condition or an inadequate captive environment being provided, often a combination of both. Traditional Chinese medicine has also played it part in ill snakes reaching our shores. Originally it was Zaocys sp. that were used but today has been replaced with many Ratsnake species, including The Mandarin Ratsnake Euprepiophis mandarinus, Beauty Snakes Orthriophis taeniurus sp., Radiated Ratsnake Coelognathus radiatus, Yellow Striped Ratsnake Coelognathus flavolineatus, 100 Flower Snake Orthriophis meollendorffi. Quiet often in the past these species arrived in the UK with there gall bladders cut out, an undetected procedure where they cut beneath the ventral scales to remove it. By taking the gall bladder out the collector was getting twice the amount of money for the snake. These animals lasted a few months in captivity. Most often the onset of death was characterized by a bright green staining on the ventral scales, at the position where the gall bladder would have been.

Snake bile has long been valued in china in Traditional Medicine, mixed with rice wine it is used as a health drink, as well as a treatment for whooping cough, rheumatic pains, fever, convulsions, haemorrhoids and skin infections. Thankfully collectors & exporters have cleaned up there acts and animals arriving now have a much better chance of survival, often fresh imports are received in the UK, meaning that they haven’t been held for months on end in mixed species pits waiting for export to this country, often without water and the high risk of parasite / disease transferral.

  Yellow  Striped Ratsnake 'Vietnam'Although C. flavolineatus has been bred in captivity a number of times it is still a relatively unknown species, often as is the case with many Asiatic Ratsnakes it is Captive Hatched animals that go on to provide us with our captive breeding stock or increase the gene pool of already established captive populations. In the past gravid Asian Ratsnake species were chosen by keepers in the hope of incubating the eggs and thus providing them with healthy captive stock. With so many difficult and fragile Asian species this may be the only way that we are able to obtain these species for the hobby.

There are a few Javanese captive bred animals imported from Europe into the UK each year and several breeders are now working with those from Vietnam, so it won’t be long before we see these beautifully marked & coloured flavolineatus appearing in the UK.

CAPTIVE CARE

TEMPERATURE

In captivity they do well with a daytime temperature range of 74-80F and a few degrees drop at night.

HUMIDITY

A relative humidity of between 70 - 75% throughout the cage is required with an additional moss box hide which should have a humidity of 90-100%. Additionally the cage should be sprayed 3-4 times a week. Humidity is vital to there general well being, and especially so when approaching a slough, when the cage can be misted on a daily basis to prevent sloughing problems.

WATER

C. flavolineatus will like other members of this genus and those of Gonyosoma drink droplets from there bodies or cage furnishing after being sprayed more readily than using the water bowl.

Quiet often they will use the water bowl to empty there bowels into, in which case the water bowl will need disinfecting, this can be done simply by first washing in soapy water and rinsing and then soaking it in a solution of Milton or any of the readily available brands of reptile cage cleaning products and rinsing thoroughly.

Fresh water should be made available each day in a clean bowl, topping up water bowls is not a good idea as scum can quickly accumulate in a warm humid environment this contains several bacteria inc. E. coli & Pseudomonas .

SUBSTRATE

My choice of substrate for this species is Sphagnum Peat Moss for the following reasons:

It is easily spot cleaned
Cheap & readily available
It has beneficial properties including natural antibiotics
Peat moss hampers the growths of bacteria, which with a species that requires a high humidity that encourages the growth of bacteria is a real bonus!
Allows natural burrowing behaviour

Yellow Striped Ratsnakes like to burrow and a soft substrate devoid of any sharp material should be used. Additionally the substrate of choice should help to maintain the high humidity that is needed by these snakes.
Regular spot cleaning is essential to stop fungal growth, but also if dealing with wild caught animals to stop the reintroduction of direct cycle parasites from rehosting the animal and further burdening the snake. Examples of direct life cycle parasites are: Roundworm, Hookworm, Strongyloides, Amebiasis all of which may be present in WC snakes. They pass the eggs in there faeces when they hatch they can either gain entry back in to the snake through there skin or contaminated water or food.

A plastic bag over your hand to scoop out any animal waste and surrounding substrate is a hygienic method disposing of the bag straight into the dustbin.

CAGE FURNISHINGS

Several hides help to make this shy species feel secure, including the obligatory moist hide. These should be placed in the cooler areas of the cage as well as the warmer. C. flavolineatus will use branches if they are made available although not known as a climbing snake they do forage in low bushes in the wild. Plastic plants attached to the branches will not only make the vivarium pleasing to the eye but also serve as an additional hide for the snakes, these will also hold droplets of water when spraying which the snake will drink from.

FOOD

In captivity C. flavolineatus will accept defrosted mice, rats & day old chicks as part of there diet. They have a tendency to pin there prey rather than constrict, although larger prey items may be constricted. They do show a marked preference for smaller food items throughout most of the year. During the months of August, September and again in January, they become feeding machines and will take any suitable sized food item offered. It is at this time that day old chicks will be taken in their diet as well as weaner rats, items that are ignored usually throughout the rest of the year. Presumably this increase in feeding is them getting prepared for the cooler months and again building them selves up on emergence from there dormant state for the coming breeding season. Males do not eat as much as the females and as such, are usually of a slimmer and smaller size.

BREEDING

C. flavolineatus like other members of this genus will lay several clutches throughout the year. The Radiated Ratsnake C.radiatus, which has been bred with some regularity in captivity has been recorded (Riabov 1997) as laying nine clutches in one year. From these clutches 100 hatchlings emerged. It was also noted that repeated fertile clutches up to 6 can be laid from only one copulation. It might also be assumed that this could be true for C. flavolineatus, we already know that they are capable of producing 4 clutches per year. Females are of breeding age at approx 3 years of age whereas the males are sexually mature by 2 years.

With so much demand being put on the female in producing multiple clutches per year, a good feeding regime must be put in place. Smaller than usual food items fed twice a weekly are taken at times of gravidity, larger prey items being steadfastly refused.

CYCLING

Brumation is not necessary for C. flavolineatus but a two month cooling period starting in November is beneficial for this species to stimulate breeding behaviour. The temperature should be maintained at approx 68F with a decrease in humidity levels and minimum light levels.

COPULATION

Courtship usually begins almost immediately up on introduction of the pairs and copulation within 15-20 minutes after this. The pair will stay hooked up for some considerable time usually 9-12 hours (Moscow Zoo 2003).

GESTATION

The gestation period for this species is approx 48-50 days.

EGG LAYING

The female will lay her eggs approx 10-12 days after her pre laying slough with each clutch containing an average of 5-7 eggs. The eggs are quite large averaging a length of 62mm, and weighing 16g. (Moscow Zoo 2003).

INCUBATION

C.flavolineatus eggs are very thick and leathery. The incubation medium can be vermiculite or sphagnum moss. Although my preference for many Asiatic Ratsnakes is sphagnum moss as it allows a good circulation of oxygen around the eggs whilst still holding them in place. A small bowl of water can be placed in the corner of the container to help with humidity levels. I also think it’s much nicer for the hatchlings when they escape the egg to burrow into something natural. Vermiculite has a habit of sticking to little ones, and if it prematurely leaves the egg with egg sac attached this too gets stuck up with vermiculite.

Too wet a medium will result in the eggs taking up to much water and splitting or drowning the developing embryo. As with other species that lay thick skinned eggs (such as The Beauty Snakes O. taeniurus sp.), a larger than average container should be used, so that there is plenty of oxygen in the container. It is quiet usual and necessary for optimum survival of the hatchlings with this and many other Asiatic sp. to manually pip the remaining eggs once the first one has pipped. The shells are very hard and it is difficult for the hatchlings in an artificial incubation environment to exit the eggs, in the wild there is possibly several natural factors that play apart in the hatchlings safe exit from the egg. Possibly the lack of calcium in their wild diets compared to that offered in captivity, which might produce a smaller degree of calcification of their eggs plays some part.

A method employed by several Ratsnake breeders for difficult to hatch eggs is to cover them with damp newspaper approximately 10 days before there expected hatch date, this helps to soften the eggs, making exit from them for the neonates easier. In some cases this has resulted in a 100% ‘natural’ hatching rate.

HATCHLINGS

Hatchlings emerge from their eggs as bright colourful youngsters measuring approx 35cm and weighing on average 16g. Their first slough takes place after 8-10 days from hatching. They can be somewhat problematic, often refusing all meals offered. Force feeding is often employed to sustain them until feeding voluntarily. Once feeding regularly, they present little problems to their keepers if their captive requirements are understood and met.


References
1. Utiger, U. Schatti, B. & Helfenberger, N. 2005 The oriental colubrine genus Coelognathus FITZINGER, 1843 and classification of old and new world racers and ratsnakes (Reptilia, Squamata, Colubridae, Colubrinae).
2. Lim & Lee 1989 Fascinating snakes of Southeast Asia
3. K.D Schulz 1996 A Monograph of the Colubrid Snakes of the Genus Elaphe Fitzinger
4. Subhuti Dharmananda, Ph.D., Director, Institute for Traditional Medicine, Portland, Oregon The Medicinal use of Snakes in China
5. Cox, M. J. 1991 The Snakes of Thailand and Their Husbandry.
6. The Snakes of Borneo Downloadable Word Doc from bsp.com.bn/panagaclub/pnhs/Projects/Reptiles/Snakes/Snake6n.doc Off Line
7. Ryabov S.A., 1997. On the Extraordinary High Productivity in Elaphe radiata. Russian Journal of Herpetology, 4 (2): 203-204.
8. 2003 Coelognathus flavolineatus (Schlegel, 1837)  (Scientific Research in Zoological Parks Moscow Zoo)
9. Roger Klingenberg Understanding Reptile Parasites: A Basic Manual for Herpetoculturists & Veterinarians (Herpetocultural Library)

This site has information on the following genera of Ratsnakes ... Spilotes, Spalerosophis, Ptyas, Zamenis, Elaphe, Rhinechis, Senticolis, Pseudelaphe, Pantherophis, Bogertophis, Orthriophis, Gonyosoma, Oreocryptophis, Oocatochus, Euprepiophis, Coelognathus, Archelaphe