Lychas mucronatus (Fabricius, 1798)
Chinese Swimming Scorpion/Ornate Bark ScorpionINTRODUCTIONOrigins & Beyond
– Known as the Chinese Swimming Scorpion alongside several other colloquial references, this typically ornate representative of the genus Lychas, is considered to be the most widespread and common scorpion species across South East Asia along with Liocheles australasiae (Vachon 1988). Its range spans from lower China, Myanmar, Laos, Cambodia, Vietnam, Thailand, West Malaysia, the Philippines and the Indonesian islands of Java and Sumatra. Their appearance on Rakata Kecil (Indonesia) after the island was effectively sterilized by the Krakatau eruption of 1883 (Vachon 1988), demonstrates its potential as a cosmopolitan species; taking advantage of human commute among other means to spread beyond its’ range to distant lands. One specimen was encountered in Norway; presumably stowed away in fresh food produce imported from Asia (Turuel & Ova Rein, 2009). In Japan, this species has been effectively introduced.Place in Human Cultural History
- Various regional cultures have utilized them as ingredients in traditional medicines or simply as food; long before the debauchery of Fear Factor Stunts. Considered a delicacy in Vietnam and Thailand, the fresh-food markets of Southern China’s rural provinces are famous for preparing them grilled on a stick and ready to eat beside squirming buckets sold by the kilos. Their appeal is in this regard warranted that these including other scorpions and arachnids are cultivated in these countries for local and regional demand (). On supermarket shelves in Bangkok city, it is not unusual to find them brand-packaged as light snacks.
Not particularly new to the hobby, their relative hardiness and exotic appearance, found enduring popularity among many exotic keepers. They have been bred in captivity with comparative ease by many individuals among which, the contributions made by Fransistek Korvarik has been held in great confidence as the most conclusive guide to their captive husbandry. Therefore I had no intention of pretentiously putting forth any notion that I have anything significantly ground breaking to add in that respect. The work I have done, aims to deliver a more pictographic guide for any hobbyist hoping to keep and breed this species from a slightly varied standpoint. The crux of which revolves around the extensiveness of their range which by all means seems to testify to their considerable adaptability which many may risk of underestimating in finite considerations with regards to their care; further emphasizing the importance of the philosophy that in keeping any species with such a wide range, it is key to know of precise origin of the specimens to approximate more accurately the specific conditions to simulate in captivity.
So in all seriousness... What’s in a name? First of all Lychas mucronatus is not exclusively from China where it is said to cohabitate with Mesobuthus martensii and thus the conditions deemed suitable for the latter, does not always apply to all specimens of the former. Secondly, its namesake is not indicative of a species being able to resist the effects of drowning. None of which sums up all there is to know about this no less remarkable, though well-known species that still holds many of its secrets to itself.Venom Toxicity & Medical Importance
– As with all buthids, this species should be handled with care as their venom toxicity ranges in severity depending on patient/victim variables. An LD50 rating has not been attained for the venom of Lychas mucronatus but accounts of stings report intense burning pain of a wide area lasting up to 8 hours.Personal Account
– While rehousing 2nd instar scorplings, one individual had crawled on to the back of my hand and while trying to brush him off into a cup, I was accidentally stung on top of my hand. I immediately felt a welting burn spot. The effect immediately spread from a prick point to an area approximately 1.5cm in diameter the moment I clenched my fist; suggesting that the venom may contain properties that react to muscular contortion. The pain inflicted from an 8mm 2i scorpling was definitely much more intense in comparison to the sting of an adult Heterometrus spinifer approximately 12cm in length; despite the retrospective size comparison of a 100 times over. The sensation lasted up to 20 minutes before wearing off rather abruptly. There was no evident discoloration of the sting site. The stings of adults are expected to be more severe. Medical Application
– Though not considered medically important, recent studies at State Key Laboratory of Virology, College of Life Sciences, Wuhan University (China), revealed that Mucroporin, a novel cationic host defence-peptide, cloned and characterized from the venom of Lychas mucronatus, showed considerable potential as an anti-infective agent against various antibiotic-resistant strains of Staphylococcus bacteria (Chao et al, 2008); exemplifying that the probability of medical importance and applicability of any naturally occurring biological compound, may not always correspond to its toxicity or severity of its effects on mammalian systematic. Speed and Temperament
– These scorpions can move considerably fast. Their speed is somewhat equal to that of various small roach species upon which they habitually prey. Their initial response to any disturbance is to retract and freeze; presumably relying on their camouflage which is remarkably effective when set against light-coloured bark. They are inclined to remain in this position even gently prodded but may suddenly bolt when adequately compelled, scurrying a considerable distance before slowing down to find the nearest refuge. If they are provoked again mid-sprint, they can take off at an even faster pace. With the exception of brooding females, they seem rather reluctant to display any defensive aggression at all. Species DescriptionAverage size:
Both sexes reach an adults length of 40-65mm from (chelicerae to telson)Species Diagnostics:
Bears all the hallmarks of a Buthid – triangular sternum; elongated build; diminutive or slender pedipalps in contrast to a muscular metasoma ending in a pronounced telson; the genus Lychas (Koch 1845) is characterized largely by a subauculear prong at the base of the vesicle; 6-cutting edges on the fingers of the chela; Dorsal mesosomal keels are prominent on the tergites except for the last mesosomal segment; metasomal segments 1-4 are distinctly keeled; 5th metasomal segment – smooth, without keels. Both sexes bear between 16-25 pectinal teeth.Sexual dimorphism
is evident in the chela shape of adult male specimens. By comparison, males have more bulbous manus, with the tibia (fixed finger) is proximally twisted and slightly concaved; resulting in a noticeable gap between the tibia and the tarsus when the chela are fully closed. Presumably, this effectively aids in courting when the male grab holds of the female’s chela in his.Coloration & Markings
– The body, legs and appendages are a yellow base, blotched with patterns of grey or brown spots. The chelicerae and interocular region of the carapace are black (Korvarik 1997). The patella of the pedipalps and the ‘fingers’ of the chela are distinctively dark bordering the distinctively light-coloured manus. The tips of the tibia and tarsus are tinted reddish brown. The posterior edge of the carapace up to the 6th tergite, has a series of bright yellow spots that flank the dark dorsal keel. The metasoma adheres to the coloration of the legs, but darkens to a deep brown at the 5th metasomal segment to the telson. Color variances may be an inherent trait of regional populations, or a conditional result of the environment in which certain specimens develop over time.Personal Notes Regarding Ambiguities and Enigmas of their Occurrence and in Malaysia
– Despite the alleged frequency of their occurence, numerous details of their natural history and ecology remain elusive. My efforts to find them in the dense undergrowth of Malaysia’s rainforest, has been all but fruitful. Though I’ve never personally encountered them, I managed to compile various accounts from those who have, in order to help piece together some idea of the environmental conditions of their specific habitat niche. Other than one or two brief descriptions of them occurring in the bark of termite-infested logs (Vachon 1988), I didn’t find any literature on studies of their natural history or ecology.
Various surveys and collection reports include that they are often found in close proximity to significant water sources, but these remain equally flippant. The only record of their occurrence in the Malaysia was made by Korvarik (1997) which for all its presumed reliability, was listed under Singapore which understandably avails very little certainty in that respect. If at all their distribution should be restricted to the northern states and the island of Penang; either of which is more attributive of its close proximity to Southern Thailand where their commonality is affirmed. Lester, however, recalled finding two specimens a couple of years back in Johor, and was kind enough to provide photos of the location where he found them.
Lester informed that he found them in the evening with a blacklight, perched out in the open on vertical bark low to the ground deep in the thicket at the base of those trees during the wet season. The area was evidently more drenched in precipitation and dense with vegetation than this picture currently portrays. He did not attempt to capture them but a return trip to the location revealed that the grass had been mowed and their occurrence had not been seen there since. Subsequent accounts from Ryokenzaki and numerous others, have reported finding them on the stems of Duku and Langsat (fruits), implicating that they may be common in agricultural plantations with conditions dissimilar to Lester’s photos. Further inquest into one of these accounts stated that the fruits of the branches they were found on were imported from Thailand by trucks. Though this is indicative of how the species may spread beyond its original range through agricultural activities that span the region, it does not negate their endemic existence in the Malaysian Peninsular, Indonesia or the Philippines, but more conclusive field study is required to attain certainty of this. It is plausible to believe that if any introduced populations of this species in the Malaysian Peninsular, they remain isolated in micro-niches or have succumbed to predation and competition characterized by distinct fauna shift that presides over the land bridge that defines the border between Malaysia and Souther Thailand. THE KEEPING & BREEDING OF Lychas mucronatus
Firstly, I would like to thank Andrew and Ryokenzaki for providing their own experiences as comparative references to supplement my report which should be noted stems primarily from my own personal experience, some research and varying degrees of trial and error. Among the many uncertainties/questions I had hoped to bring to light regarding this species through this project include: -
i. As a centrally arboreal (semi-arboreal) species, what elements of their natural history do they fulfill by burrowing?
ii. What are the conditions that influence choices between burrowing vs. arboreal lifestyle options?
iii. What strategies do they adopt for prey capture?
iv. To what extent do they live up to their common name as ‘swimmers’ (outside chucking one in bowl of water)? Captive Conditions
– Ideally, any scorpion enclosure should aim to replicate the natural environment to which the species is suited. Knowing “where your specimens come from,” is key when dealing with a species so widely distributed across invariable climate conditions. It is plausible to expect specimens from Southern China to have hardier resistances to cold and dry, as opposed to those from populations originating from Southern Thailand where the climate is more tropical. Brief Specimen LogMaterials studied:
3 Lychas mucronatus (3rd instar) CHPurchased from:
Andrew AKA Leetplayer (October 2009)Source of Specimens:
Southern Thailand – tropical humid environment; region experiences the most rainfall throughout the year with lows of about 21.7c to highs of about 33.6c; implicating that a mesic setup would be more suitable for these in comparison to much drier conditions implemented for specimens presumably from Southern China. Housing:
Kept separately as juveniles and sub-adults; kept communally when fully-matured.Temperature & Humidity Conditions:
the specimens were kept at a constant average 27.9c (82.2F) with lows of 24.6c (76.3F) to highs of 31.2c (88.2F), without adhering to natural temp fluctuations of the specified region. In general, humidity levels were kept relatively high; in accordance to the alleged origins of the specimens. The treatment appropriated was to mist the enclosure heavily and overflow its waterdish every alternate day DIET:
Juveniles and Subadults: fed small German cockroaches or small crickets every 3 to 4 days.
Communally – Housed Adults: given 1 or 2 appropriately sized crickets (per scorpion) every weekCommunality
– In the wild, Lychas mucronatus have been known to live together in large ‘colonies,’ but as with many other communal bark species, cannibalism is reputed to occur with freshly-molted or molting individuals. Therefore, it is best to keep juveniles or sub-adults separately until they reach adulthood; assuming the survival of each precious specimen is a primary concern. This species allows hobbyist the opportunity to keep a thriving colony of adults in a sizeable habitat enclosure provided there is sufficient food and hiding spaces. COMMUNAL ENCLOSURES FOR ADULTSType 1: Kritter Keeper (Guppy Tank) Enclosures
– When housing L. mucronatus in any widely available plastic Kritter Keepers (Guppy Tanks), it is sensible to tape up the lower ventilation slits from the inside to minimize any chances of escape. An added safety measure would be to ensure that the top of the enclosure is well beyond the scorpions’ reach.
After one initial trial run, I found these enclosures to be not particularly suitable, other than temporary housing solutions at best. Despite their apparent convenience these enclosures tend to lose moisture and humidity rapidly without unless a sufficient amount of ventilation is compromised. As a result, they would require more frequent hydration than most people can exercise. Furthermore, plastic tends to get scratched over time, resulting in surfaces rough enough for these scorpions to scale.Type 2: Communal Habitat Vivariums
– The ideal housing for any Lychas would be vivarium habitats set in large cylindrical glass jars as stated by Kovarik or cube aquariums. With cylinders, the risk of young individuals scaling the silicone corners of aquariums is eliminated. For my matured specimens I used a 20cm cube glass aquarium with a custom-built lid. The snug-fitting lid is fitted with fine mesh for ample topside ventilation and a feeding tube for minimal disturbance. Vivarium Setup
– Having never encountered them in the wild, I had limited reference regarding the natural surroundings to emulate for the purpose of observing natural behaviour. Nonetheless, the arboreal or semi-arboreal nature of the species would suggest the need for vertical bark climbs, moisture retaining substrate, wide but shallow waterdish, not to mention the region from which these specimens derived. SETUP TUTORIAL
The process of putting this setup together is briefly explained in the following pictorial sequence.
Inserting some form of plant matter i.e. leafy fern stalks into the enclosure is substantially beneficial if not vital to the well-being of Buthid species from South East Asia. These collect water droplets from which they habitually drink. Additionally, they provide added shelter, since they like to hide on open spots of bark shaded by leafy plant growth.
Live plants would be the ideal component but may impose considerably laborious upkeep duties. These also require constant light to sustain indoors, which is often incompatible with the scorpions’ nocturnal orientation. Despite requiring occasional replenishment, bush trimmings and clipped fern stalks prove a convenient alternative in the respiratory aspect in comparison to artificial plant decor. This I must maintain is a personal standpoint and should by no means dictate the practice of other individuals in accordance to their respective preferences.
As the colony grows, the enclosure can be augmented appropriately to provide enough hiding places for more individuals. These are some pictures of the setup as it progressed over time.THE BREEDING & HUSBANDRY OF LYCHAS MUCRONATUS
In the short time which I’ve kept them, I had the privilege of successfully breeding this species in captivity. Being the prolific breeders that they are, this was much easier to achieve than I ever anticipated. All in all, both of my female study specimens bred twice; giving me a total of 4 broods. Successful Breeding:
14/03/10 – Female1 gave birth – 28
21/03/10 – Female2 gave birth – 19
17/05/10 - Female1 gave birth – 22
24/05/10 – Female2 gave birth – 16
The 2nd batch was born while all survivors of the 1st batch have yet to reach full maturity. Because no mating was personally witnessed and no spermatophore was found, it was difficult to determine if the 2nd batch resulted as a systemic brood, or from subsequent matings. Nonetheless, since gestation for this species has been stated at approx 3 months, I took a rough note of expected time period when and further minimized any disturbance to the enclosure.
26/02/10, a decrease night-time activity was observed in both females during the dry cycle. .They were seen residing behind the vertical bark pieces at opposite ends of the enclosure; remaining poised and motionless not unlike a hibernative state. Close examination of the pleural membrane revealed the presence of faintly visible embryos. Females approaching parturition were seen to indicate a darkening of the pleural membrane where the embryos were visible during the initial stages of development.First Batch 14/03/10
– Female1 was found with a clutch of 2nd instar scorplings during one of my unobtrusive routine checks. They were likely born a couple of days prior during the dry cycle; suggesting that parturition may occur during the seasonal droughts when the scorpions seek refuge deep in the hollows of tree roots earth underground.
21/03/10 - While Female1 was still in weaning off her scorplings, Female2 was found with a clutch of 1st instars on her back. Both females were isolated and rehoused in their respective brooding containers.
While carrying a brood, females are fiercely aggressive towards tankmates or anything that comes too close. It is best to isolate brooding females to avoid any untoward events with other adults in the community. Leetplayer’s photographic account confirms that when housed in an insufficiently sized enclosure, a brooding female may cannibalize a wayward tankmate. Furthermore, moving her from the communal tank would be less problematic than removing her tankmates and allowing her brood to run free around the communal adult habitat.Brooding Containers
– Essentially, these receptacles function as nurseries for mothers to complete their maternal vigil undisturbed, until the scorplings enter their first moult and are subsequently weaned. The nursery should contain all the necessary elements used in an adult enclosure except for an open waterdish. The picture below shows the jar I use as a brooding container. Based on previous observations of my study specimens, the mother does not feed throughout her maternal vigil, so no reason to be overly concerned about infanticide/brood cannibalism.
Moving Brooding Mothers is a widely discouraged practice in the hobby. However, untoward circumstances may deem this to be unavoidably necessary. For Lychas mucronatus and other bark scorpion species, their instinctive behaviour can be exploited for the benefit of this task in accordance to standard handling and transfer practices for all potentially hot or species. A brooding female situated on a manageable bark piece will freeze in response to any movement of the bark; making it easy to extract it along with her on it. Holding the bark with tweezers is presumably the safest, but I do this with bare hands for better grip as opposed to the danger of the bark slipping the tweezers’ grip.
While the female remains in stasis on the bark, steadily move the bark to the brooding 88888888888container you prepared earlier for this purpose. Place the bark in a secure position in the brooding container and wait for her to move off that bark on her own. Alternatively that bark piece can simply remain in there if the container can accommodate it.
If the female should move during this process, don’t panic and let her do her thing. At no time at all should the female ever be prodded or coaxed into moving. Place a bark piece in her path and she will oblige without hesitation. Never try to cup her with bare-hands as they will strike out with their metasomas defensively and this will most likely result in envenomation. First Instars
– The 4mm larvae are glutinous representatives of their parents, bearing elements of the adult coloration but lack the prominent segmentations of the adult form. The actual birth was never witnessed but there is reason to believe that the female seeks a hollowed refuge and total darkness for this process. A short video clip has been uploaded on youtube by (x) revealing post-parturition behaviour (include link). As usual the young are not able to feed during stage as the mouthparts have yet to be fully formed.First Ecdysis to 2nd Instar
– Roughly 6 days after parturition, the young enter their ecdysis to become 2nd instars; which is slightly longer than duration documented by Korvarik (2006) as 4 days, but due to the fact the birth was rarely witnessed, the time frame is difficult to accurately ascertain. The young are miniature replicas of their parents averaging 6mm in lengths.
When the 2nd batch of scorplings of Female2 entered their 1st moult, an unusual maternal behaviour was captured on video. The mother secreted a liquid from her gut which the young will drink from her chelicerae. I wasn’t aware about this until I reviewed the footage of the babies molting on the mother’s back (video evidence provided).Burrowing Behaviour in Brooding Females
Another interesting behaviour, consistently observed in the maternal vigil of this species was burrowing. Despite being characteristically arboreal, this species is known to be relatively proficient at constructing deep burrows at the base of roots, using their long slender pedipalps and legs to scrape aside debris. They sometimes use their chela to move and allocate specks of debris with decisive precision; a seemingly painstaking but effective method. It is not strange to find the opening of used crevices lined if not with bits of plugged with coco-fibre as an apparent means to completely encase themselves. Even while carrying a brood on her back, both of my female specimens have dug crevices at the base of a vertical bark to make chambers below the substrate surface.
The most plausible motive behind their burrowing inclinations seems to be the need for moisture. It is reasonable to think this captive behaviour is an alternative resolve such circumstances when they require similar conditions in the hollows of tree roots underneath the surface during droughts.
Shortly after the 1st ecdysis (roughly 4 days) the scorplings will start to leave the mother’s back in stages. I observed female2 cutting through narrow spaces to encourage the young on their way, but in way should any attempt be made to intervene for the purpose of hurrying this process along. Furthermore, it is ill-advised to extract any free-roaming scorplings from the nursery while the brood remains partially in mom’ care. Allow all the young to effectively leave the mother before taking her out and putting her back in the communal enclosure. It should be noted that females are ready to immediately breed again following the customary gestation period. Both my females gave birth to their 2nd brood before while their 1st brood was still at 4th going on 5th instar. Anyone hoping to breed this species can expect wave after wave of consecutive broods to keep them well occupied!Raising and Feeding 2nd Instar Babies
– Once the mother has been removed, the brooding container can effectively serve as a nursery for the now free-roaming 2nd instar babies. This is the most crucial time for the young scorplings as they are officially on their own. Presumably, in the wild they will disperse to feast on numerous of insect fry and micro-inverts. In captivity however, this is difficult to marginally replicate. In the absence of pinheads, I resorted to keep the broods communally at least until they fatten up for next moult. In this way, larger prey items can be given with the benefit of scorplings mobbing and sharing kills. Chopped up mealworms and cricket legs will suffice to a certain degree, but because they react primarily to fast moving prey items, these tit-bits are not always completely consumed.
For the first two batches, I used these miniature kritter cylinders to house them communally. It was expected that a few individuals will succumb to cannibalism when they start molting into 3rd instars, but there is no reason to exclude this as a natural occurrence in the wild. Despite this inevitable misfortune, most of the brood tend to group together in tightly packed clutches.Transferring Scorplings
– When a number of individuals have been observed molting or being cannibalised as a result, this brief communal arrangement was appropriately substituted for individual housing. Allowing some cannibalism to occur helped to thin out the brood and prioritize resources for fewer but hardier individuals. Handling 2i Lychas mucronatus for the purpose of transfer and re-housing is an exercise in patience. Since most of them adhered to the bark, it was simply a matter of picking up a bark piece and gently maneuver. them one by one, with a soft paintbrush onto the bark piece in the new receptacle. The toughest problem faced in this task is the scorplings natural instinct to flee upwards. They also have the knack for free-falling, so conduct this in a safety basin at all times. Scurrying scorplings can also be retrieved by placing a piece of bark in front of them.
Individual Housing for Juveniles and Sub-Adults – Raising Lychas mucronatus is essentially no different than raising other bark scorpion species. Standard specimen vials, or plastic delis with substrate and vertical bark works across the board, but depending on where your specimens originate, the treatment for temperature and humidity may vary accordingly. Scorplings advancing the communal hatchery were set up in mini-delis seated in a larger tub as a safeguard.
For 3rd to 4th instar, I used medicine vials readily available at most Pharmacies. Since, Rafiqos and Rasputin concurred that dehydration and insufficient ventilation seem to be the main cause of death in captivity, I administered an ample amount of side ventilation to each these vials.
Once they reach 5TH instar in these vials, an enclosure with more room like medium-tall delis are recommended for the final moult into maturity.
I have not found it necessary to provide a bottle-cap for water, as long as the container is sprayed frequently to maintain desired humidity levels. Moisture evaporates relatively quickly in plastic containers like these; especially when sufficient ventilation is required. If you’re keeping them in a country where the climate is dry, a small bottle cap of water might be necessary but this will not diminish the need to spray on a frequent basis. Leafy plant stalks are particularly vital as reservoirs of accumulated water droplets.Feeding & Dietary Preference
– With the first batch, I tested a variety of fodder that was conveniently available at the time to discern any preference in prey items. Despite repeated attempts, tweezer-fed mealworm bits are entertained briefly before being disinterestedly discarded by 2nd and 3rd instars. In the event that pinheads are not readily available for this stage, Ryokenzaki and me, found cricket drumlets, a good alternative albeit requiring a little more convincing. This along with occasional caches of small roach fry were given as a staple for the communal clutches (refer to notes on feeding).
Ultimately, they respond primarily to movement. German cockroaches (Blatella germanica) are notably favoured among other tested prey types; provoking an immediate hunting response. They advance stealthily with outstretched chela before fervently snatching their quarry while immediately administering the sting to pacify their prey (refer to notes on prey capture). Juveniles will even take roaches slightly larger than themselves but show little interest in much smaller crickets.
Due to their fragile nature, they are reluctant to take on prey capable of causing them significant damage. At 3rd and 4th instar, small mealworms can be given, but it would crucial to ensure that its circumference would not present a problem for the chela to acquire a firm grip. Comparable discrepancies have been observed with providing them Dubia roach fry (Blaptica dubia), as fodder.
By 4th instars to maturity, any prey item suitably appropriate to the scorpions’ size is fair game; including mealworms and dubias. At this stage they are capable of subduing prey many times their size but will only consume their fill before discarding any leftovers, thus it is sensible to give them appropriately sized prey items to minimize to the need to remove mite-magnets. Some hobbyist may regard the practice of giving considerably large prey items as power-feeding, which I must maintain as a last resort in the limited options of fodder available to me, as a opposed to intentionally stuffing them silly. Nonetheless, the advantage gained here is that each scorpion may require only 2 to 3 large prey to reach the next instar in due time.Behavioural Observations in Prey Capture
The hunting behaviour of L. mucronatus has been described awhile back by Rasputin, whose account on the matter was not particularly dissimilar from my own personal observations. Emerging from their hiding places in the late evening, presumably after rains, they seek vertical perches overhanging water puddles which typically serve as insect magnets. Clinging face-down from their perches with chelas outstretched ready to pounce; depending heavily on their speed and toxicity to snare and immobilize any passing prey below or within reach; grabbing hold of any extremities such as legs, wings, antennae etc., while pulling back the prey against their forward-stabbing metasomas. This forceful attack ensures penetration of the auculus. This strategy of subduing prey is consistently observed throughout all instars. Some feistier individuals have been observed running down their roach quarry which suggests that L. mucronatus have relatively good ocular vision as well.Correlation between Humidity Levels Sustained in Captivity with Burrowing Behaviour, Ecdysis & Growth Rate
– All 3 of my study specimens molted successively into maturity at 6th instar to an adult length of 44, 42 and 41 respectively. The rate of development was reasonably consistent with Korvarik’s life table (Korvarik), if not a bit faster – a probable result of the temperature humidity levels I was able to conveniently maintain and the intake of comparatively large prey items. Since, any observed burrowing behaviour corresponded evidently to considerable drying out of the enclosure, this was seen as an indication these scorpions indeed preferred conditions that were moister/more humid . By contrast they rarely burrowed if conditions were kept sufficiently moist or humid. The rationale behind this is that the need to burrow in times of drought, expends a considerable degree of energy. Energy which can be allocated to growth if not expended for that purpose. When conditions were moist, the scorpions adhered to the bark, ever poised to respond to any prey stimuli. Sustaining moist conditions for this species was also seen to be important to sustain for ecdysis (moulting). Ecdysis
– Unlike new world bark scorpions that typically hang face down using gravity to aid in ecdysis, L. mucronatus usually moults face-up, clinging to a vertical bark. Some individuals will moult-flat on the ground without any difficulty; suggesting that vertical surfaces are not the absolutely required despite it being essential to its arboreal nature. As mentioned before, conditions conducive to this process lean towards slightly wet and humid; as pre-moult individuals seem to be urged into molting shortly after a generous misting. It is perfectly fine to leave the substrate slightly wet as they will cling to bark during this process.
Those kept in moderately moist conditions will sometimes moult on the substrate; inferring that moisture and humidity is crucial for this process. It is likely that moisture is absorbed by the scorpion to aid in increasing its body’s internal pressure; making the molting process less strenuous. Furthermore, individuals have been noted to stay in pre-moult stages for extended time periods if kept in relatively dry conditions resembling more temperate climates as opposed to tropical. Note that sub-adult individuals pending and imminent moult will be restlessly ‘wagging’ their metasomas from side to side. Arboreal vs. Semi-Arboreal
– In consistence with the previous discussion, I would have to sustain my opinion that Lychas mucronatus are generally arboreal in nature with occasional semi-arboreal tendencies. Notions regarding their intermittent inclinations as inferences towards them bordering on semi-arboreal/opportunistic burrower, appear to be more conditionally circumstantial than innate. Considering their preferred refuge of choice as observed in the large communal vivarium , I can only hypothesize their most probable environmental niche would have to be bark crevices and decaying tree hollows low to the ground; as depicted by what little is stated regarding their natural history. In drier times, it is reasonable to presume that they take refuge deeper in the ground among the tangle of tree roots in search of those preferable conditions. Though this may seem to suggest the validity of them being described as semi-arboreal, it is clear that the essential nature of their lifestyle i.e. prey capture, habitual residence, routine activity etc., defines the centrality of their arboreal nature. Whilst there has yet to be any reports finding them many meters up in the tropical canopy, this remarkable species is as arboreal as scorpions come.What’s in a Name? Can they really swim? (Dedicated to Michiel)
– I have yet to throw one in an aquarium full of water with partially submerged branches to effectively determine this. I believe however, their common name is a result of over-imaginative assumptions. The only behaviour depicting their affinity to water I have since observed is one of the females standing stilt legged over the shallow water dish after it was sufficiently filled and overflowed.
There is however, one possible explanation to how their alleged name came about. Whenever the enclosure was hydrated after an unusually long dry out, they will come close to the water dish and perch themselves vertically face down to groom themselves meticulously with their chelas, legs and telsons. Their body appears to be coated over by some oily secretion, reflecting the demure of a human swimmer towelling down after a number of laps. This behaviour may have given the impression that they are capable of swimming; a proposed feat to which I remain disappointingly skeptical. Areas for Further Study
– L. mucronatus are said to co-exist with Mesobuthus martensii (Chinese Armor-Tailed) In China the distribution of both species may overlap in certain areas despite the later being more suited to regions of drier temperate climate. A captive experiment involving the co-habitation of these two species is definitely a longed-for venture.
It has been a pleasure working on this species which I had longed for almost 20 years to experience 1st hand. Last but not under UV light; the intricate markings that define this species are still evidently distinctREFERENCES
1. Chao Dai, Yibao Ma, Zhenhuan Zhao, Ruiming Zhao, Qian Wang, Yingliang Wu, Zhijian Cao,* and Wenxin Li*
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China Copyright © 2008, American Society for Microbiology
2. Kovařík, F. 2006 Breeding of the scorpion Lychas mucronatus. Lychas mucronatus (Fabricius, 1798)
3. Kovařík, F. 1997 Revision of the Genera Lychas and Hemilychas; with descriptions of six new species (Scorpiones: Buthidae)
4. Nguyen D.N.V. and Nguyen T. 2008 An Overview of the Use of Plants and Animals in Traditional Medecine Systems in Vietnam – A Traffic Southeast Asia Report
5. Pocock R. I. 1900, the Fauna of British India Arachnida: Scorpiones: Buthidae
6. Turuel & Ova Rein, 2009
7. Vachon, M. 1988 Colonization of the Krakatau Islands by Scorpions; Acta Arachnol 37