Brazilian Black Tarantula

Brazilian Black Tarantula（圖片來源：André Karwath aka Aka，採用 CC BY-SA 2.5 授權）

The Brazilian black tarantula (Grammostola pulchra) is a terrestrial spider native to Brazil and Uruguay in South America. Its entire body is covered with dense, velvet-like black setae, giving it a calm and dignified appearance. With its gentle temperament and impressive size, it is widely regarded as an ideal beginner species for those interested in keeping large tarantulas. In the wild, this spider commonly inhabits dry grasslands, shrublands, and open plains. It typically shelters beneath rocks or inside burrows originally made by other animals. Rather than digging deep tunnels on its own, it tends to exploit natural crevices and existing cavities as refuges.

The defensive behavior of the Brazilian black tarantula is relatively mild. Like many members of its family, it possesses small urticating hairs that may be flicked when threatened. However, compared with most related species, this behavior occurs less frequently. When disturbed, the spider usually prefers retreating or fleeing rather than attacking. Its venom is considered weak and poses little danger to humans.

Adults can reach a leg span of around 18 centimeters. Females are exceptionally long-lived and, under proper care, may survive for more than 30 years, while males typically live only 6 to 8 years. Their growth rate is slow. Females often require 7 to 8 years to reach full maturity, whereas males generally mature within 4 to 5 years. Spiderlings are initially brown or dark gray, gradually turning into a glossy deep black after successive molts, resembling a layer of velvet covering the body. Although this transformation takes time, many keepers find the gradual change particularly rewarding.

In nature, Brazilian black tarantulas are nocturnal predators that mainly feed on insects and other arthropods, occasionally attacking small lizards or rodents. Their dark coloration provides excellent camouflage against soil and nighttime surroundings, helping them avoid detection by predators such as birds or snakes. Because Brazil maintains strict regulations on the export of wild specimens, most individuals available in captivity today are captive-bred descendants.

Brazilian Black Tarantula（圖片來源：Mike Peel，採用 CC BY-SA 4.0 授權）

Housing Requirements in Captivity

In captivity, Brazilian black tarantulas are relatively easy to maintain, but careful attention must be paid to safety, temperature, and enclosure design. As a terrestrial species, their enclosures should emphasize floor space rather than height. Excessively tall enclosures increase the risk of injury if the spider climbs and falls. For adult individuals, the enclosure should ideally measure at least three times the spider's leg span in length and width, typically around 50 centimeters.

Suitable substrate materials include pesticide-free organic media such as coconut fiber, peat moss, or leaf litter soil. A substrate depth of approximately 15 to 20 centimeters is recommended. Juveniles especially enjoy burrowing and can benefit from slightly moist substrate that allows them to construct tunnel-like shelters. Adult individuals, however, generally prefer a dry and well-ventilated environment, with only a small corner of the enclosure kept slightly moist.

A simple enclosure layout is sufficient. Providing a half-round shelter or similar hide allows the spider to feel secure without requiring overly complex decorations. The optimal temperature range is around 20 to 24°C. During colder seasons, a low-wattage heating pad attached to the side of the enclosure can help maintain stable temperatures. Humidity should remain around 60 percent. The environment must not become excessively damp, as high moisture encourages mold growth. A shallow water dish should always be present and cleaned regularly.

To reduce bacterial growth, adequate ventilation is essential. Air holes should be present on both sides and the top of the enclosure to allow air exchange while retaining moderate humidity. When these conditions are maintained, the spider can establish a stable and relaxed lifestyle similar to its natural rhythm in the wild.

Feeding Conditions

Brazilian black tarantulas primarily feed on insects. Spiderlings can be offered wingless fruit flies, small mealworms, or tiny crickets. As the spider grows, the diet can gradually shift to medium-sized crickets, Dubia cockroaches, or larger mealworms. When using live prey, it is important to observe whether the spider captures the food promptly. If the prey remains uneaten for more than half a day, it should be removed to prevent the insect from injuring the spider or decomposing within the enclosure.

Adult individuals can be fed once every two to three weeks. A typical feeding consists of four to five large crickets or one Dubia cockroach. If the spider's abdomen appears noticeably swollen, it indicates sufficient nutrition and feeding intervals can be extended. If the abdomen appears slightly thin, feeding frequency may be increased moderately. Overfeeding can lead to obesity, interfere with molting, or even cause abdominal rupture, so controlling portion size is essential.

After a molting event, feeding should be postponed for several days to a week. The spider's chelicerae must first darken and harden before prey is introduced. Feeding too early may damage the mouthparts. In addition, insects captured from the wild should never be used as food because they may carry parasites or pesticide residues that could harm the spider. Using captive-bred feeder insects and maintaining a clean enclosure environment helps ensure stable feeding behavior and long-term health.

Breeding Conditions

Male Brazilian black tarantulas typically reach sexual maturity between 5 and 8 years of age, while females may require 8 to 12 years before becoming reproductively capable. Mature males develop specialized hook-like structures on the front legs known as tibial hooks, which are used to secure the female during mating. The pedipalps also enlarge at the tips, forming structures that function as sperm transfer organs. Before mating, the male constructs a sperm web, deposits sperm onto the web, and then loads the sperm into his pedipalps before searching for a receptive female.

Prior to pairing, it is advisable to ensure that the female has been well fed in order to reduce the risk of aggression toward the male. Some breeders simulate seasonal changes by temporarily lowering temperatures and reducing feeding frequency before gradually returning conditions to normal, mimicking the natural rhythm of the rainy season. When the male is ready, he can be introduced into the female's enclosure at night. The male will drum the ground with his front legs, producing vibrational signals directed toward the female. If the female is receptive, she may remain still or respond with similar vibrations. The pair then proceeds with mating. After copulation, the male should be removed immediately to prevent accidental cannibalism.

Following successful fertilization, the female usually produces an egg sac after approximately four to six months. Each egg sac typically contains between 100 and 300 eggs, which require about eight to ten weeks to hatch. If the female is allowed to care for the egg sac naturally, the spiderlings generally remain together through two or three molts before dispersing. If artificial incubation is used, the eggs should be maintained at about 23°C with humidity near 60 percent and gentle ventilation. Males usually die within several months after mating.

Breeding this species presents challenges due to its long maturation period and the relatively short lifespan of males. Because Brazilian black tarantulas are protected in their native range and the export of wild-caught individuals is prohibited, captive breeding remains the only legal method for sustaining captive populations and supplying the pet trade.

Preventing Invasive Spread

The Brazilian black tarantula is native to South America. If individuals are intentionally released, abandoned, or accidentally escape in non-native regions, they could potentially affect local ecosystems by preying on native insects or small reptiles, thereby disrupting ecological balance.

For this reason, keepers must strictly follow the principle of never releasing or abandoning captive animals. If the owner can no longer provide proper care, the spider should be transferred to a responsible keeper or an authorized animal shelter rather than being released into the wild.

When purchasing this species, it is essential to choose captive-bred individuals in order to discourage the illegal collection of wild populations in their native habitats.

Author: Shui-Ye You