#Amphibians Basic Information and Husbandry Guidelines for Alytes muletensis, Mallorcan midwife toad Stand: 01.04.2021 I Alytes muletensis I Foto: Ole Dost Content 1. Characterisation 2. Why is Alytes muletensis a Citizen Conservation species? 3. Biology and Conservation 3.1 Biology 3.2 Threat Situation and Protection 4. Husbandry 4.1 Conditions and Documentation Requirements 4.2 Transport 4.3 Socialization 4.4 The Terrarium 4.5 Lighting, Temperatures, Humidity 4.6 Feeding and Care 4.7 Breeding 4.8 Rearing of Offspring 4.9. Husbandry Problems 5. Further Literature Stand: 01.04.2021 1. Characterisation Scientific name: Alytes muletensis (SANCHIZ & ADROVER, 1979) Vernacular name: Mallorcan Midwife Toad, Balearic toad Length: 3.5-4 cm CC#Amphibians category: IUCN Red List: Endangered (EN) Protection status CITES (Convention on International Trade in Endangered Species): no Protection status on European level: Annexes II and IV of the Habitats Directive Housing: Preferably in groups of six animals or more in terrariums of approx. 80 x 30 x 40 cm (length x width x height) with mineral substrate (gravel etc.), many hiding places (layered cork bark, stone slabs etc.) and a removable water bowl with low water level. Moist and dry hiding places. Temperature range 15-25 °C. Year-round indoor keeping without real hibernation (wintertemperatures in the lower range of the temperature range). Diet: All common food animals up to the size „cricket medium“ are eaten (crickets, fruit flies, waxworms, isopods etc.). Even small toadlets can eat small crickets etc. Breeding: Reproduction possible all year round, peak in the summer half-year. Clutches are wrapped around the legs of the males and carried until the tadpoles hatch. Rearing of the tadpoles in aquaria with approx. 1-2 tadpoles/L without further technical equipment. Feeding with fish food, brewed nettles etc. Long larval phase of up to 18 months, tadpoles then very large. Stand: 01.04.2021 I Alytes muletensis I Foto: Philipp Ginal 2. Why is Alytes muletensis a Citizen Conservation species? In the beginning, there were a few fossil bones. When scientists B. Sanchíz and J. A. Alcover described the toad Baleaphryne muletensis after finding these remains of a Middle and Upper Pleistocene amphibian from the Balearic island of Mallorca in 1979, they assumed that the species had been extinct for about 2,000 years. The surprise was all the greater when, in 1980, researchers on an expedition to the site where the bones were found in the Serra de Tramuntana came across lively representatives of these amphibians. And that in the middle of the much-traveled vacation island Mallorca! The Mallorcan midwife toad can stand symbolically for our highly incomplete knowledge about amphibians. Surprises can never be ruled out, while at the same time we have to fear that many species are actually becoming extinct, sometimes even before we have discovered them. Pastor and nature photographer Ole Dost is CC‘s godfather for the Mallorcan midwife toad Stand: 01.04.2021 I Alytes muletensis I Foto: Ole Dost This threat is also symbolized by the Mallorcan midwife toad. The distribution area of the species today is only about 10-20 km2 - species with such small areas must basically be considered endangered, since a single catastrophic event could wipe them out. The fact that this toad can only be found in such a small area is already the result of human influence and thus typical for an important cause of endangerment of amphibians: Alytes muletensis used to be widespread on Mallorca, but was probably pushed back in ancient times by new species introduced by humans: on the one hand, by the viperine snake (Natrix maura), which is an effective predator, and on the other hand, by the Iberian water frog (Pelophylax perezi), which also eats Mallorcan midwife toads, but also competes directly with them. The remaining habitat is threatened by extensive agriculture and human settlement. Another threat is the recently introduced chytrid fungus Batrachochytrium dendrobatidis (Bd). The International Union for Conservation of Nature (IUCN) now classifiesAlytes muletensis as „endangered“ (EN). It therefore makes sense to keep a reserve population in human care, to fall back on in case of emergency - such as a dramatic population collapse in the wild. Alytes muletensis, like all midwife toads, exhibits spectacular reproductive biology and can thus provide an example of the fascinating variety of unusual amphibian reproductive strategies. Male Mallorcan midwife toads wrap eggs strings around their hind legs, carry them around until the tadpoles hatch, and release the hatching larvae into a suitable body of water. Through this highly developed brood care they increase the survival chances of their offspring enormously. Finally, the Mallorcan midwife toad is a charismatic, easy-to-observe and easy-to-keep species, making it well suited for keeping by less experienced persons or for school vivariums, and therefore can serve as an ambassador for both the diversity of amphibians and their global threat situation. Stand: 01.04.2021 I Alytes muletensis 3. Biology and Conservation 3.1 Biology Midwife toads of the genus Alytes occur in six species in the Mediterranean region. They belong to the family Alytidae together with the Discoglossus and Latonia. Alytes muletensis, with a length of about 3.5-4 cm, is the smallest and least bulky midwife toad. Its body structure seems rather frog-typical: its legs and fingers are longer than those of other midwife toads, the head is large and rather strongly flattened. The sexes in Alytes muletensis cannot be distinguished with certainty externally outside the reproductive phase. Pregnant females are more plump, and the ovaries may sometimes be visible. Males carry eggs strings after egg laying. In general males are somewhat slimmer, females are slightly larger on average. The large eyes with vertically slit pupils are conspicuous in the Mallorcan midwife toad. Its basic coloration is cream to yellowish with darker, greenish-black to brown „leopard spots“. There is sometimes a black triangular marking behind the eyes. The ventral side is whitish and without markings. Today A. muletensis only occurs in a ten square kilometer area in the Serra de Tramuntana in the northwest of Mallorca. There the species inhabits 30-70 meter deep rocky gorges at elevations between 30 and 850 meters above sea level. Torrents flow through these gorges, which dry up in summer except for small pools. These permanent pools are critical for larval development. However, midwife toads also use artificial water bodies in the vicinity of the the gorges. The adult animals live in crevices, caves or under stones of the the karst mountains and are usually not seen, but only heard in the wild. The small toads are mainly nocturnal. MALLORCA Palma Distribution of Alytes muletensis in Mallorca according to the IUCN Red List: The remaining original habitat is colored orange, the purple areas mark reintroduction areas. Stand: 01.04.2021 I Alytes muletensis Habitat in Mallorca I Foto: Dawn Flemming/Durrell Wildlife Mallorcan midwife toads live in the crevices of these rocky Conservation Trust gorges I Foto: Dawn Flemming/Durrell Wildlife Conservation Trust Breeding in Mallorca takes place between February and September. In February, the males begin to call. This „frog concert“, often compared to a chime, stimulates the females to form eggs. Calling also serves as a form of territorial behavior. Males „mark“ their preferred calling sites. When another male approaches, especially if a female is present, the competitor is decisively pushed out of the way. Females also call in response to males, to initiate mating, and in disputes with conspecifics over mates. When there is a surplus of females, females also make display calls to attract attention (BUSH 1997). The reproductive behavior of midwife toads is unusual. All midwife toads engage in intensive brood care that is unique among amphibians. Egg-laying takes place on land, usually in May for Alytes muletensis. To do this, the animals go into amplexus, where the male clasps the female by the loins. Stand: 01.04.2021 I Alytes muletensis During oviposition, the male fertilizes the eggs with his sperm and then wraps the egg strings, which contain 7-34 (usually 10-12) eggs with a diameter of 5-7 mm, in a complicated procedure around the hind legs, where they are „tied up“ in the area of the thighs. In the process, the male sometimes pulls part of the egg string straight out of the female. This process is similar in all Alytes species and is responsible for the name „midwife toad“. The scientific genus name also refers to this unusual specialization: „alytos“ in Greek stands for „tied up“. The egg strings are extremely tear-resistant when out of the water, and with the eggs inside, they look like strings of pearls. In the beginning the eggs are yellowish to white but soon one can already see the two dark spots that mark the eyes of the larva. The male carries the eggs, which become darker and darker as they develop, for about 3-4 weeks (reports range from 11-65 days), during this time it retreats to damp places to prevent the eggs from drying out. However, it can also mate with other females during this time and also take their spawn. From June onwards, the male goes to a body of water where the connections of the egg strings soften in the water and finally dissolve. The male assists his self-release by vigorously kicking with his hind legs. The tadpoles break through the egg shell and then swim away. They are just under 2 cm long at the time of hatching. Now it takes another 2-3 months for larvae hatched early in the year and growing up under favorable climatic and food conditions, and 12-18 months for larvae hatched la- ter and growing up under cool temperatures or meager food resources until metamorphosis.