Scorpions of the Genus Tityus in Captivity: Care, Breeding and Life History
Page 1 of 4 | text by Oliver St John, photos by Alexander Tietz
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Preface to E-Zine Article
This article was published in ARACHNOCULTURE 1(4) in late 2005. It has not been edited or updated for this late 2009 E-Zine publication. Nomenclature may not reflect current scorpion taxonomy.
Introduction
Scorpions of the genus Tityus are among the most dangerous scorpions in the world, accounting for many deaths and injuries in the tropics every year. However, they have recently become extremely popular additions to scorpion collections, primarily in Europe and increasingly in the US. This is due to their great diversity in morphology, colouration, behaviour and, no doubt in part, to their notoriety. This article will cover the general care and breeding of Tityus species and briefly look at the various species currently in the hobby.
Tityus in Captivity
Tityus (Koch, 1836) is the largest genus in not only the Buthidae, but of all scorpion families. It is also one of the most studied scorpion genera, with new species frequently. Yet for a long time it was surprisingly underrepresented in captivity. In the past, only T. serrulatus was readily available to European collectors. A breeding population of T. falconensis had also been established in Europe for some time, with T. trinitatis also occasionally available. Recently, however, breeding populations of several other Tityus species have been established in Europe and the United States including T. bahiensis, T. paraensis, and T. costatus. Some of these species are still rarely available, but with time should eventually be readily available to the hobbyist.
Tityus species are a desirable addition to a live scorpion collection not only due to their rarity, but also the many attractive colour and morphological variations the genus displays. They are often fast growing, readily breedable, and give birth to a considerable number of offspring, making them ideal species in which to observe complete life cycles. But they are not good beginner scorpions, and must only be kept by highly experienced keepers. This genus ranks among the most venomous scorpions, and in Central and South America is responsible for many deaths and thousands of envenomations every year. Much of this is due to human encroachment into their natural environment, forcing opportunistic scorpions to adapt to life in close contact with humans (Lourenço et al., 1996).
Despite the notoriety of these species, they are comparatively docile in captivity and typically far less defensive than other buthid scorpions presently in the hobby. All Tityus species covered here can be kept in similar conditions. As they are primarily sit-and-wait predators, they require very little space and do well in enclosures as small as 10 x 10 x 10 cm [4 x 4 x 4 in]. Coming from tropical regions, Tityus species generally enjoy high humidity. Standing water is not required as, like other scorpions, they seem to get most of their moisture from their prey; they may supplement by drinking condensation. These species seem to enjoy high temperatures, thriving at daytime temperatures of 27-32°C [80-90°F]. With regular feeding and good conditions, scorplings suffer a very low mortality rate and can be easily raised to maturity. Subadults are all prone to cannibalisation (especially after moults) and it is advisable to separate them at the second instar, the moment they leave the mother's back. Some of the species mentioned can be kept communally when adult.
Most species of Tityus are approximately the same size (2 in [5 cm] in total length). Captive bred specimens are generally substantially smaller than wild-caught adults. The information presented here is based upon personal observation from hobbyists who keep these species in captivity supplemented with data from the literature.
Tityus serrulatus Lutz & Mello, 1922
Of all the Tityus species available in captivity, T. serrulatus is probably the easiest to keep. It is also the most readily available member of the genus with established populations in the United States and Europe. Tityus serrulatus is a small scorpion and captive-bred adults reach approximately 40-50 mm [1.5-2 in] in length (prosoma to telson). It is very common in Brazil and often found in association with humans, which is why it is responsible for many envenomations every year. It is a dangerously venomous species with an LD50* of 0.43 mg/kg (sc, Simard & Watt, 1990). However, they are relatively docile when threatened and will only use their venom if seriously provoked. This species was initially thought to consist solely of females that reproduce parthenogenically, but a small sexual population was recently discovered (Lourenço & Cloudsley-Thompson, 1999). This species is comparatively easy to raise and keep. In captivity they are semi-arboreal, resting either on the ground or climbing slightly above the surface. They are fairly tolerant of each other and adults can be kept in large communal groups (Candido and Lucas, 2004). Subadults will, however, cannibalise each other postmoult. They enjoy high humidity, yet seem to be very tolerant of drier conditions. All the specimens in captivity are females that will readily reproduce by parthenogenesis. Well-fed adults will produce offspring in about 3-4 months; brood sizes in captivity seem to average about 17 scorplings (with broods ranging from 15-25). Scorplings take about 12-14 months to reach maturity, reaching adulthood in the 6th instar. Lifespan in captivity is about 4 years. Females can produce up to four broods of scorplings during their lifetime (Matthiesen, 1971), though three is more common. T. serrulatus has recently been the subject of some taxonomic debate. Lourenço has proposed (Lourenço & Cloudsley-Thompson, 1999) that it is not a separate species but rather the confluenciata morph in the Tityus stigmurus complex, though this change has not been recognised by some researchers (Fet et al., 2000). This debate should not concern the hobbyist much, but it highlights interesting questions about the relationships of some species in this genus.
* LD50 is a standardized measure for expressing and comparing the acute toxicity of a chemical such as venom. LD is an acronym for "lethal dose". LD50 is the amount of chemical that when administered in a single dose results in death of 50 percent of the test animals. Rats and mice are usually used in the tests and the LD50 value is typically expressed in milligrams of venom per kilogram of animal body weight. The lethal dose can be computed for various means of entry into the animal, but "sc" (subcutaneous [under the skin]) injection is most common. In this article, "ip" (interperitoneal [into the chest cavity]) is also used.