Vivariums;reptiles;Mangrove Monitors

3- Mangrove Monitor :

The mangrove monitor,[2] mangrove goanna, or Western Pacific monitor lizard (Varanus indicus) is a member of the monitor lizard family with a large distribution from northern Australia and New Guinea to the Moluccas, Solomon Islands, Marshall Islands, Caroline Islands, and Mariana Islands. It grows to lengths of 3.5 to 4 ft (1.1 to 1.2 m).

Mangrove monitor

Conservation status

CITES Appendix II (CITES)

Scientific classification:

Kingdom:Animalia

Phylum:Chordata

Class:Sauropsida

Order:Squamata

Suborder:Lacertilia

Family:Varanidae

Genus:Varanus

Subgenus:V. (Euprepiosaurus)

Species:V. indicus

Binomial name :

Varanus indicus
(Daudin, 1802)[1]

Taxonomy :

The mangrove monitor was first described by the French herpetologist François Marie Daudin in 1802.[1] Daudin's original holotype of a subadult specimen was collected on Ambon, Indonesia, and has since disappeared from the museum in Paris. Daudin's original name for the species was Tupinambis indicus, an appellation it would carry for 100 years until being renamed as a Varanus.[3]

The generic name Varanus is derived from the Arabic word waral (ورل), which translates to English as "monitor."[4] Its specific name, indicus, is Latin for the country of India, but in this instance it relates to Indonesia or the East Indies, where the animal was first described.[3]

Due to its large geographic range, V. indicus is considered a cryptic species complex of at least four species: Varanus indicus, Varanus doreanus,Varanus spinulosus, and Varanus jobiensis.[5] More research is being done on possible future species within this complex, not surprisingly, since it has had over 25 different scientific names since it was first described.[3]

Distribution and habitat

The mangrove monitor's range extends throughout northern Australia, New Guinea, the Solomon Islands, the Marshall Islands, the Caroline Islands, and the Mariana Islands, where it inhabits damp forests near coastal rivers, mangroves, and permanent inland lakes. It also occurs on the Moluccan islands of Morotai, Ternate, Halmahera, Obi, Buru, Ambon, Haruku and Seram. Within this range of thousands of miles across hundreds of islands are large variations in size, pattern, and scalation.[3] The monitors have also been introduced to Japan since the 1940s.[6] Like the introduction to Japan, some herpetologists believe this animal's dispersal from the East Indies to smaller Pacific islands was facilitated by Polynesians to provide a meat supply. However, other scientists maintain this is not likely, as the monitors would compete with man for food, grow slowly, and yield little meat.[7]

Anatomy and morphology

The monitor's body is dark green or black in color and covered with golden-yellow spots, with light coloration on the top of its head and a solid, cream-colored belly lacking dark markings.[3] It has a distinct dark purple tongue and serrated teeth.[3][8] The mangrove monitor attains different sizes in different parts of its range, but seldom if ever exceeds 1.5 m in total length.[3] Australian herpetologist Harold Cogger gives a total length of 100 cm for Australian specimens.[9] The tail is almost twice the length of the body and laterally compressed to aid in swimming. Like the rest of the lizard's body, it is covered with small, oval, keeled scales.[8]

This monitor has the ability to increase the size of its mouth by spreading the hyoid apparatus and dropping the lower jaw to eat large prey, a process similar in appearance to that of snakes, although the jaw of the mangrove monitor remains rigid.[10] The mangrove monitor possesses a Jacobson's organ, which it uses to detect prey, sticking its tongue out to gather scents and touching it to the opening of the organ when the tongue is retracted.[8]

The mangrove monitor is one of only two species of monitor lizards, the other being V. semiremex, that possess salt-excreting nasal glands, which enable them to survive in saltwater conditions and to consume marine prey.[7] The presence of this gland probably enabled the monitors to reach new islands and aid in its dispersal throughout the Pacific.[8]

Diet :

The mangrove monitor is an opportunistic carnivore, feeding on the eggs of reptiles and birds, mollusks, rodents, insects, crabs, smaller lizards, fish, and carrion.[9][11][12]Mangrove monitors are the only monitor capable of catching fish in deep water.[13] In some parts of its range, it is known to eat juvenile crocodiles.[3]

Mangrove monitors in the Southern Mariana Islands shifted major prey classes when their regular prey began declining.[6] The monitors were known for eating shrews on Guam,[4] but the introduction of the brown tree snake (Boiga irregularis) led to decreased shrew numbers, prompting the monitors to switch to eating invertebrates and foraging through human garbage.[4][6]

Reproduction

The species lacks distinct sexual dimorphism, but mature male monitors on Guam have been reported to be three times the mass of mature females.[4] Males fight for females, and in one observation, after mounting the female, the male used his chin to rub the dorsum of the female's head and forequarters.[6] While mounted and oriented head to head, the male and female slowly rotated in a clockwise direction through 360°, with the male remaining superior.[6]

Female mangrove monitors lay two to 12 eggs that measure 3.5 to 5 cm in length. The oblong eggs are white, and hatch in about seven to eight months.[14]

The first successful captive breeding of this species was at the Philadelphia Zoo in 1993.

The Reptilian Zoo in Vlissingen, the Netherlands,[15] was reported to have successfully hatched eggs by a female animal which was not in any contact with a male of the same species.

Contact with humans

Humans have introduced the mangrove monitor to a number of Pacific Islands since the 1930s.[12][16] They have been present on Ifaluk in the western Caroline Islands since the Second World War.[16] The Japanese introduced the lizards to the Marshall Islands prior to World War II to eliminate rats; the lizards flourished and soon began to raid the local chicken houses.[12] When American troops arrived, the locals asked them for help in getting rid of the mangrove monitors. The US response was to introduce the marine toad (Bufo marinus) which proved toxic to the lizards.[12] As the monitor population dropped, however, the rat population began to rise.[12] Marine toads were introduced to the Palau Islands for a similar reason, and the demise of the mangrove monitors led to an increase in numbers of beetles known to be harmful to coconuts.[16]

The mangrove monitor is hunted in many places for its skin, which is used for leather in making drum heads.[17][18] Although international trade in this species is small, Mertens referred to it as one of the most heavily exploited monitor lizards.[18] In 1980, trade in over 13,000 monitors was declared. However, in many remote places, they are used as a food source and are killed because of their reputation for preying on domestic animals.[8] An ethnic group on Guam eats the monitors as a traditional food, and a business there sells monitors for food.[6]

The United States Department of Agriculture’s Animal and Plant Inspection Service announced it will use a combination of two poisons, diphacinone and brodifacoum, to kill off the rodents on Cocos Island. They will also attempt to lower the mangrove monitor population on Cocos Island by 80%, using several trapping methods proposed by herpetologist Seamus Ehrhard, as the lizard is believed to prey upon the endangered Guam rail (Gallirallus owstoni). Most locals, however, do not see the monitor as an invasive species and a few activists are opposed to the attempt to lower the population there.

Mangrove monitors are often kept in zoos and private collections, as they are an active and alert, and generally can be handled if tamed properly.[11] Most specimens defecate on their handlers when stressed.[8] With proper care they can live up to 20 years in captivity.[11]

Head of a mangrove monitor, Muséum National d'Histoire Naturelle, Paris

For the external links , refrences click here to read the full wikipedia article

Video :

Handling my Mangrove Monitor (Varanus Indicus)

Care Articles :

1- MANGROVE MONITOR

courtesy to : www.reptilesmagazine.com/Lizard-Species/Mangrove-Monitor/

MANGROVE MONITOR

Varanus indicus

-Family: Varanidae

-Adult Size: Moderate in length, with most adults averaging between 2½ and 4 feet in total length.

-Range: Throughout the Mariana, Caroline, Marshall and Solomon Islands; as well as Celbes, Timor, New Guinea and northern Australia.

-Habitat: Warm, humid areas. In trees near rivers and streams.

-Captive Lifespan: 12 to 20 Years

-Dangerous:

-Care Level: Advanced

Overview :

The mangrove monitor is semi-aquatic and arboreal by nature, spending much of their time in or near water. Captive mangrove monitors need a warm, humid, spacious cage with branches for climbing and basking and a large water container for swimming and soaking. Hide boxes or other shelters are also recommended for the mangrove monitor species.

Captive mangrove monitors will consume fish, frogs, lizards, snakes, eggs, mice, small rats and canned cat or dog food.

Mangrove monitors require temperatures ranging between 82 and 90 degrees Fahrenheit, with a warmer basking spot (up to about 95 or 97 degrees Fahrenheit). Nighttime temperatures can be lowered to around 70 or 75 degrees Fahrenheit. A thermal gradient is recommended.

2- MANGROVE MONITOR LIZARDS

courtesy to : reptiliana.wordpress.com/

LENGTH: Varanus indicus ranges from 75 to 120 cm in length. The head is long and narrow, with the neck longer than the head. The tail is almost two times the length of the body and strongly compressed.
COLORATION: dark colorations with various small, yellow spots. The iris is dark brown with a golden ring surrounding it, and the palpebrals that surround the eye are sulphur yellow while the remaining surfaces of the eyelids are white. Also, the mouth is sometimes outlined with red and this may attract prey or frighten predators. Komodo dragons show a similar coloration. The red substance is actually blood mixed with saliva.
The Mangrove Monitor has four strong, well developed legs with five, sharp, clawed toes. TEXTURE: The face is smooth and glossy, with large scales. The body and tail are covered with small, oval, keeled scales. The teeth are serrated along their anterior and posterior edges, with the dentary teeth directed slightly laterally and the maxillary teeth directed vertically.
COOL FACTS: A special characteristic of this monitor is that it possesses the ability to greatly increase the size of the mouth by spreading the hyoid apparatus and dropping the lower jaw in order to eat large prey. Another special characteristic of this monitor is that they have no taste buds on their tongue, but they may have taste buds on the roof of their mouth. Although the tongue has no taste buds, it is highly specialized for chemosensory function and is frequently protruded.

HABITAT: Varanus indicus occurs in the Pacific from Japan to southern Australia and on many of the islands of the Pacific. Man-aided dispersal from the East Indies to some small pacific islands was facilitated by Polynesians in order to provide a meat supply. It is not known whether all these island locations were natural or man-aided dispersal. The monitors were also introduced to Japan from the Japanese in the Marshall Islands before World War II. The habitat of V. indicus consists of damp river banks and in coastal forests.

BEHAVIOR: The Mangrove Monitor can be characterized as being an “opportunistic predator” as far as feeding behavior. A study done in 1993 showed that V. indicus in the Southern Mariana Islands shifted major prey classes reflecting changes in the available prey base. The following regular prey of V. indicus have been declining: A land snail, Achatina fulica , has been greatly reduced due to the introduction of the predaceous flatworm, Platydemus manokwari, populations of slugs have been greatly reduced because of the introduction of the Cane Toad, Bufo marinus, and the shrew populations on Guam are low because of the introduction of the Brown Tree Snake. When V. indicus have been observed in captivity, males tend to be more aggressive than females, and if males feel threatened, they don’t bite, but rather defecate on the perceived threat. No courtship behavior has been observed. In one observation, after mounting the female, the male used his chin to rub the dorsum of the female’s head and forequarters. It was also observed that while mounted and oriented head to head, the male and female slowly rotated in a clock-wise direction through 360 degrees with the male remaining superior. They are extremely shy animals.

DIET: The diet of V. indicus consists of small mammals, insects, crabs, bird eggs, birds, and other lizards. A study done in the Northern Mariana Islands and the Territory of Guam between the years of 1989 and 1991 showed the diet of V. indicus, in non-urban settings, consisted of 45% arthropods, 13.6% terrestrial crabs, 27.2% scincid and gekkonid lizards and their eggs, 4.5% of Ramphotyphlops braminus, and rats made of the rest of the diet, at 9.1%. In urban situations, additional food in their diet included domesticated chicken eggs, squid (a common fishing bait), and aluminum butter wrappers.

REPRODUCTION / GROWTH: The clutch size of female V. indicus is about 2-12 eggs, and is smaller than would be expected of a medium sized monitor lizard because female V. indicus are very small. A female observed in Guam laid 22 eggs over a period of three years in clutches of 1-4 eggs. A captive female laid 25 eggs in five clutches over 26 months, with an average of 88 days between the last four clutches and 4-6 eggs in each clutch. The varied clutch sizes indicates that the monitors tend to reproduce continuously when food is abundant, producing large numbers of relatively small clutches. The eggs are about 3.5 – 5 cm in length, are oblong and white, and hatch in about seven to eight months. No care are given to the young by the parents when they hatch. Guam is the only place where a nesting site has been seen, and it was found in guano deposits of a cave-dwelling bird, Aerodromus vanikorensis. The site contained only egg shards. A characteristic of courting exhibited by males involves showing both physical and behavioral control over the female. Males also fight for females. A study done in 1998 looked at the reproductive ecology of V. indicus on Guam. Adult lizards acquire energy stores in the form of fat bodies to meet energy demands during reproduction. In females, stored fat is mostly used for egg production, but in males, the use of fat is not well understood but it could be used for a variety of activities, including reproductive behavior, such as searching for females, courting, mating, and territorial defense, rather than just for spermatogenesis. The results of this study showed that ovarian mass is greater during the dry season for females, the minimum body size at sexual maturity is greater in males than females, and that males have testicular sperm year-round. Fat body mass in males did not differ between seasons, but female fat body mass was greater during the dry season than during the wet season. Reproduction of V. indicus on Guam seems to occur during the dry season (January to April). The reproduction occurring during the dry season can be explained by looking at egg incubation periods and food availability for juveniles. When the young hatch during the wet season, insect abundance is greater, meaning more food for the young.

CONSERVATION STATUS: There is no entry on the Red List 2000 for V. indicus . The major populations of V. indicus include Australia, Guam, Indonesia, Japan, the Marshall Islands, Micronesia (Federated States of), Northern Mariana Islands, Palau, Papua New Guinea, and the Solomon Islands. In 1994, there was a decline of V. indicus on Guam and the Mariana Islands that could have been due to the effects of urbanization. Also, farmers on these islands see the monitors as pests and try to trap, shoot and poison them because they have witnessed the monitors attacking their domesticated fowl. There is an ethnic group on Guam that eat the monitors as a traditional food, so a business exists to sell the monitors to them. The introduction of the Brown Tree Snake, Boiga irregularis, and the poisonous Cane Toad, Bufo marinus , are also known to affect the monitor population on these islands. Lastly, the mangrove monitor has a beautiful skin and as a result is hunted in many places for its leather. There were CITES export quotas in 1997 and 1998 in Indonesia.

3-Mangrove Monitor care sheet

courtesy to : www.reptileforums.co.uk/forums/lizard-care-sheets/500076-mangrove-monitor-care-sheet.html

Overview

The Mangrove monitor is known to science as Varanus indicus. This is one of the most wide spread and versatile monitor lizards in the world. These lizards have been introduced to a number of Pacific islands to control marine toad and rodent populations. In fact, they are so wide spread and variable that the Mangrove monitor complex includes some of the most beautiful and taxonomically debated species available in the pet trade.
The Mangrove monitor is found in New Guinea, Northern Australia, Solomon Islands, Marshall Islands, Caroline Islands, Marianas Islands, Guam as well as other Pacific Islands (Bennett, 199. With such a wide distribution it's no surprise that there are a number of different patterns and color phases associated with the Mangrove monitor. They are usually found around bodies of water in habitats such as mangrove swamps, forests and sometimes in open areas.
The Mangrove complex includes varanids such as Varanus doreanus, Varanus jobiensis, Varanus yuwonoi, Varanus caerulivirens and of course the variable Varanus indicus. There are also many color varients of the Mangrove. There are rare blueish colored phases as well as Mangroves with blue tails that are sometimes seen. Locality data on such monitors are not clear to this author but it seems the blueish colored Mangrove is local to Halmahera. This just goes to show how diverse a group the Mangrove complex is.
I referred to these monitors as versatile because they are excellent diggers, climbers and swimmers. They can do it all. The mangrove monitor exibits the typical Indonesian monitor body shape. It has a long head and neck with powerful jaws and sharp teeth that can crush mullosk shells as well as inflict deep wounds on an unweary keeper. The limbs are powerfully built and are equiped with needle sharp claws that are good for digging and climbing. The tail is typically about 1.5 times as long as the body or SVL (Snout to Vent Length) and is laterally compressed to aid this accomplished swimmer. The tail can be spotted or banded in whatever color the markings on the body are. The dorsum is black and variable in pattern and most commonly shows some form of transverse or random spotted markings. These markings are anywhere from white to yellow and can vary in size. The lips are usually of a cream color
There is little captive breeding going on for these lizards and most of the animals seen in the pet trade are WC (Wild Caught). As always, you should try to buy a CB (Captive Bred) animal whenever possible but this is not always an easy task with most species. It has been documented that most Mangrove monitors in the trade come from the Solomon Islands. Wherever they come from it is important that you treat WC animals for parasites and bacterial infections when they come in. However, this is not always neccessary and a keeper will need to use their judgement to do what is needed to establish the animal in captivity.

Heating and Lighting Requirements

Mangrove monitors come from an area of the world that has hot humid temperatures for most of the year. They will need the same in captivity in order to thrive. Heating can be provided through the use of heat lamps. These come in a number of different forms. There are "reptile" basking lights on the market that do a good job at providing the needed heat for your monitor but they tend to become quite costly after a while. The same amount of heat can be obtained from an inexpensive halogen bulb from the hardware store. Bulbs come is a number of wattages and some experimenting on your part will be needed to determine which bulb(s) is best suited for your enclosure. Varanus indicus will bask at high temperatures and a basking spot with a surface temperature around 120°F will be used often. Monitor the temperature and be sure it doesn't become too hot as themal burns may occur. The rest of the enclosure should have an ambient temperture gradient of 80-90°F. It is important to avoid a uniformly hot tank because this will put stress on the animal and it will not be able to thermoregulate properly. Depending on the size of your enclusure you may find it neccessary to use ceramic heaters to maintain the correct temperature gradient. These are good for background heat since they produce no light and are effective against combatting low night time temperatures. Warning: Make sure your Mangrove monitor can not come into direct contact with the heating element because it can severely injure itself. Their sense of touch is not the same as ours and the monitor may burn itself without knowing it. Use some sort of screening or make sure the heating device is far enough away that the monitor can't reach it.
If you feel your enclosure is not bright enough with just the heat lamps there are a number of flourescent fixtures you can buy and install for a low price that will provide more light for the monitors.
A regular photoperiod of 12 hours light : 12 hours dark can easily be achived with the use of a simple timer that can be purchased at any hardware store. Don't be affaid to experiment with this cycle to see if there is a better light to dark ratio for your monitor or if it makes no difference at all. I won't get into the whole issue of whether or not monitors need UV lighting, except to say that there is no definitive proof to show that they need it in captivity or to show that they suffer from receiving it. Many people have successfully kept monitors both ways. You can do some research and make your own informed decision on this one.
Mangrove monitors should be protected against low night time temperatures. This can be done with room heaters, ceramic or night lights (usually blue or red). Try to avoid dipping below the 70°F mark at night.

Housing a Mangrove Monitor

As juveniles Mangrove monitors can be housed in various sized aquariums for the first part of their lives. A hatchling can easily live in a 30 gallon aquarium for the first few months of its life. However, it would be a good idea to buy or build an enclusure that will be able to house the monitor at its adult size from the start. This can end up saving you time, space and money in the long run. Suitable enclosures can be constructed rather inexpensively from melamine and glass. As a minimum, I would suggest and enclosure with dimensions 6 feet long X 3 feet high X 2.5 feet deep. This is only a suggestion . Of course a bigger enclosure will always be better for the monitor.
Juvenile mangrove monitors are usually skittish and will feel much safer if you give them a few hiding areas. Hiding areas don't have to be complex and can be easily constructed out of wood or a cardboard box. Of course these are not always the most pleasing things to look at but remember, functionality is more important than esthetics.
Varanus indicus is also an accomplished climber and will benefit from the addition of a few sturdy branches in the enclosure. These branches should be securely fastened to the insides of the tank and be thick enough to support the weight of the monitor. Furtharmore, Mangrove monitors are excellent swimmers and will definitly enjoy long soaks in a large water bowl. If you can provide a container that is large enough for the monitor to curl its tail around and submerge itself completly you will probably find that the monitor will spend a lot of time there. With all the splashing of water that can take place it is important that the keeper monitors the substrate so that it does not become overly wet which can result in the formation of mold. I find that by using a tall Rubbermaid tub and filling it only half or three quarters of the way full will prevent excessive spilling.
As for substrates, there are many choices available to a keeper. Newspaper, aspen shavings, cypress mulch and soil are all acceptable. I like cypress mulch for its ability to hold moisture as well as it's nice looks. A combination of soil and mulch also works well but can be a little messy. If you can provide a substrate with a little depth to it (6 or 7 inches) this will be good. Mangrove monitors will dig and bury themselves under the substrate. This can help them preserve moisture as well as feel secure in their surroundings.

Feeding Your Mangrove Monitor

Juvenile Mangrove monitors will accept a wide variety of prey items. However, they can be shy feeders and may not accept food in your presence. Don't be alarmed if your newly purchased hatchling monitor doesn't run down and consume the first few food items you offer. Some animals will feed greedily right from the start while others may take quite some time before they feel comfortable enough to eat in front of you. Just leave the food in the tank with the monitor and more than likely it will disappear in a short while.
Acceptable food items for juvenile monitors include: crickets, mealworms, mouse pinkies and hoppers, ground turkey, feeder fish and eggs. Juveniles should be fed everyday until you feel comfortable with their progress at which time you can move to every other day. Remember, you will know your monitor best and should be able to set up the most appropriate feeding regimen.
As adults, Varanus indicus will be able to accept crickets, mealworms, mice, small rats, chicks, ground turkey, eggs and various seafoods and crustaceans (i.e crayfish). Obesity is a factor that must be considered in adult monitors. Again, you the keeper will have to decide what type of diet your Mangrove will need in order to stay trim. Note: Fresh water should be available at all times

Size and Temper of a Mangrove Monitor

Varanus indicus can grow rather large and there are confirmed cases of animals growing up to 5 feet TL (Total Length). This seems to be the exception rather than the rule though. In most cases Mangrove monitors will reach lengths of 3.5-4 feet TL. Hatchlings are reported to emerge from the egg at 9-10 inches TL. If fed well these monitors will grow rapidly.
Mangrove monitors are well known for their skittish behaviour. Many of the WC (Wild Caught) juveniles that come into the pet trade will be nervous and shy at first. I have read that CB (Captive Bred) hatchlings that are handled often are much tamer initailly than their WC counterparts. This is not to say that WC Mangrove monitors are beyond taming because it is indeed possible. Of course it would be wise to start with a juvenile if this is your goal. WC adults on the other hand may prove more diffecult to tame. Regular, gentle interaction with the monitor would be the best route to take but you have to remember that a WC adult has quite a few years of experience behind it and getting it used to being handled may not be easy . Persistence is the key. All monitors have some line of defense. Mangrove monitors are capable biters and scratchers. They may even lash out at an agressor with the tail. What they are most notorious for is defecating on the handler so be aware and be ready to clean up a few messes. They also possess sharp teeth that can do damage to an un-gloved hand. Gloves are an excellent way of handling monitors without the added worry of being bitten. They are also very fast and can jump out of your grip and take off on floor before you have time to react. Be alert when handling Mangroves.

Other websites :

- www.reptipro.com/care-sheets/lizards/57-mangrove-monitor-varanus-indicus-care-sheet.html

- www.backwaterreptiles.com/monitor-lizards/mangrove-monitor-for-sale.html

- www.iucnredlist.org/details/178416/0

- reptile-database.reptarium.cz/species?genus=Varanus&species=indicus

- www.lizardtypes.com/mangrove-monitor/

Videos :