Striped Knee Tarantula
Species Description

The Costa Rican Zebra Tarantula, scientifically known as Aphonopelma seemanni, takes its common name from the striking striped pattern on its legs that resembles zebra markings. The genus name Aphonopelma translates from Greek as 'without sound' and 'sole of foot,' referencing the observation that these tarantulas do not stridulate (produce sounds by rubbing body parts together) like many other species. The species name seemanni honors Danish naturalist Berthold Carl Seemann, who contributed significantly to Central American natural history studies in the 19th century.

Alternate common names include the Striped Knee Tarantula, Costa Rican Stripe Knee, Stripe-Knee Tarantula, and occasionally Seemann's Tarantula. The names all reference either the distinctive leg striping or geographic origin. In the hobby, the species is often simply called 'the Zebra' when context makes the full name unnecessary.

The species belongs to the family Theraphosidae and represents one of several Aphonopelma species found in Central America. Aphonopelma is primarily a North and Central American genus with the highest diversity in the southwestern United States and Mexico. The Costa Rican Zebra represents one of the more southerly members of the genus, found in Costa Rica, Nicaragua, and Honduras, with possible occurrence in Guatemala.

Some specimens display notable blue iridescence, particularly when freshly molted. This structural coloration appears in certain lighting conditions and adds to the species' visual appeal. The presence and intensity of blue coloration varies between individuals and fades as the next molt approaches.

The Costa Rican Zebra Tarantula is a medium-sized theraphosid with adults achieving leg spans of 5-6 inches (12-15 cm). Females are typically larger and more robust than males, maintaining stockier builds throughout their lives. The body is compact and well-proportioned, characteristic of terrestrial burrowing tarantulas adapted to life below ground.

The most distinctive feature is the striking leg coloration that gives the species its common names. The legs display a bold pattern of alternating dark (black to dark brown) and light (white to cream) bands, concentrated particularly around the patellae (knee joints). This striped pattern creates the zebra-like appearance that makes the species immediately recognizable. Fresh post-molt specimens display the most vivid contrast, with crisp white bands against deep black backgrounds, while pre-molt individuals appear more muted and brownish.

The carapace and abdomen are typically dark brown to black, sometimes showing subtle structural blue iridescence when viewed under appropriate lighting conditions. This blue sheen, caused by light refraction rather than pigmentation, is most visible in freshly molted specimens. A fine white line often runs along the border between the carapace and chelicerae, complementing the leg striping. The overall appearance creates a cohesive, visually striking spider.

Sexual dimorphism becomes apparent at maturity. Males develop the typical mature male characteristics including tibial hooks on the front legs, enlarged pedipalpal bulbs for sperm transfer, and a more slender overall build. Males also develop longer legs relative to body size. Females maintain a more robust appearance with larger abdomens capable of producing egg sacs containing hundreds of spiderlings. The lifespan difference is dramatic, with females potentially living 20-35 years while males rarely exceed 5-7 years and die shortly after reaching maturity.

The Costa Rican Zebra Tarantula possesses a generally calm and docile temperament, though individual variation exists within the species. Most specimens prefer retreat over confrontation, quickly withdrawing into their burrows when disturbed. This retiring nature makes them relatively safe to keep, as they rarely display aggressive behavior. However, their temperament should not be confused with handleability, as their skittish nature creates different challenges.

The primary defensive response is rapid retreat, often at surprising speed. When startled, a Costa Rican Zebra may bolt suddenly and unpredictably, making handling risky despite their calm underlying disposition. This fast-moving nature makes them poor candidates for regular handling, as escaped specimens are difficult to recapture and falls from hands can cause injury. Some individuals may also kick urticating hairs when stressed, though this is less common than in some other New World species.

Burrowing behavior dominates the species' activity patterns. Younger specimens are particularly inclined to excavate extensive burrow systems, sometimes rearranging substantial amounts of substrate. Adults may be content to adopt provided hides rather than digging their own, but many maintain burrowing tendencies throughout life. This behavior means keepers should expect to see their spider infrequently, as the animal spends much of its time concealed underground.

Nocturnal activity increases slightly as night falls, when the spider may position itself near the burrow entrance awaiting passing prey. Some individuals become bolder over time, spending more time visible at burrow mouths or even venturing into open areas of the enclosure. However, extensive daytime visibility should not be expected, and keepers should appreciate the species for its secretive nature rather than expecting display-animal behavior.

Feeding responses are typically enthusiastic once the spider detects prey vibrations. They are ambush predators that strike rapidly when prey ventures within range. Post-feeding, they may remain near burrow entrances or retreat underground to consume their catch. Like all tarantulas, they will refuse food prior to molting, sometimes for extended periods.

Housing a Costa Rican Zebra Tarantula emphasizes horizontal space and substrate depth over vertical dimensions. A 5-10 gallon enclosure provides adequate floor space for adults, with 5 gallons representing the minimum and larger enclosures always appreciated. Glass terrariums, Kritter Keepers, or acrylic enclosures all work well, provided they offer secure lids and adequate ventilation. The enclosure height should be limited to prevent dangerous falls, as terrestrial tarantulas can suffer fatal injuries from drops.

Substrate selection and depth are critical considerations for this burrowing species. Provide at least 4-6 inches of moisture-retaining substrate, with deeper layers ideal for encouraging natural burrowing behavior. Appropriate substrates include coconut fiber (coco coir), peat moss, vermiculite, organic potting soil, or mixtures thereof. All substrate should be organic and free from fertilizers, pesticides, or other chemicals. Avoid sand, gravel, pebbles, or sharp substrates that could injure the tarantula.

The substrate moisture gradient is important for this species. The deeper substrate layers should be kept slightly damp while the surface remains drier. This arrangement mimics natural burrow conditions where the spider can access humidity at depth while the surface stays relatively arid. Achieve this by moistening substrate before adding it to the enclosure, allowing the top inch or two to dry out naturally while maintaining moisture below. This approach also prevents mold issues that arise from surface moisture.

A hide should be provided, typically a cork bark tube or half-round positioned partially buried in substrate. Many adults will adopt the provided hide rather than constructing elaborate burrows, though some individuals continue excavating regardless. Position the hide to allow the spider to modify it according to preference, as many will excavate beneath and around the cork to create a customized retreat.

Temperature should remain between 70-85°F (21-29°C), typically achievable at room temperature without supplemental heating. If heating is necessary, under-tank heaters on thermostats work well, but should be placed on the side rather than directly under burrow areas. A shallow water dish should always be available, refreshed regularly, and positioned away from the primary hide area. Misting is generally unnecessary if substrate moisture is properly maintained at depth.

Costa Rican Zebra Tarantulas are insectivores with straightforward dietary requirements. Their diet should consist of appropriately-sized live prey including crickets, dubia roaches, mealworms, superworms, and similar invertebrates. Prey size should not exceed the width of the tarantula's abdomen to ensure safe consumption. Larger spiders can occasionally take larger prey items but should not be given anything they struggle to subdue.

Feeding frequency varies with age and individual metabolism. Adults typically eat every 10-18 days, depending on the size of the spider and prey items offered. Spiderlings and juveniles should eat more frequently, approximately every 7-14 days, to support their growth requirements. Overfeeding should be avoided, as obesity can develop and potentially cause health issues. A moderately plump but not distended abdomen indicates appropriate feeding levels.

Gut-loading prey insects before offering ensures the tarantula receives optimal nutrition from each meal. Feed prey items nutritious foods (vegetables, commercial gut-load diets) for at least 24 hours before offering to the spider. This practice passes those nutrients through to the tarantula, improving the quality of what would otherwise be a less nutritious meal.

Very small spiderlings under approximately 1/3 inch may struggle with standard prey items and benefit from pre-killed food until they grow large enough to overpower live prey. Freshly hatched pinhead roaches or fruit flies are appropriate for the smallest specimens. As spiderlings grow, they can graduate to progressively larger prey items.

Fasting before molting is normal behavior that may concern inexperienced keepers. The spider may refuse food for weeks or occasionally longer as it prepares to shed its exoskeleton. This is natural and should not prompt force-feeding attempts or excessive worry provided the spider otherwise appears healthy with a reasonably plump abdomen. After molting, wait at least a week before offering food to allow the new exoskeleton, including fangs, to harden fully.

Clean water should always be available in a shallow dish. Remove uneaten prey within a few hours if not consumed to prevent mold, pest infestations, or stress to the tarantula. Roaches that won't bother the spider can be left longer, but crickets should be removed relatively quickly as they may nibble on a molting or stressed tarantula.

Costa Rican Zebra Tarantulas are hardy animals that rarely suffer health problems when provided appropriate care. Their adaptation to semi-arid conditions gives them resilience to humidity fluctuations that might stress tropical species. Most health issues in captivity result from environmental problems, particularly excessive moisture leading to mold or bacterial issues, or inadequate molting conditions. With lifespans potentially exceeding 30 years for females, these tarantulas represent significant long-term commitments that reward attentive keepers with decades of companionship.

The Costa Rican Zebra Tarantula's hardy constitution makes it forgiving of minor husbandry variations, but this should not substitute for proper care. Their impressive potential longevity means that attention to proper husbandry pays dividends over decades of keeping. Regular observation and maintenance of appropriate conditions ensure these beautiful tarantulas thrive for their full lifespan.

Despite their generally calm temperament, Costa Rican Zebra Tarantulas are not recommended for regular handling. Their primary challenge is not aggression but rather their tendency to bolt suddenly when startled. This unpredictable, rapid movement makes them difficult to control and creates risk of falls, escapes, or defensive responses. Experienced keepers typically minimize handling for this species, appreciating them as display animals rather than interactive pets.

When handling is necessary for enclosure maintenance or rehousing, approach slowly and deliberately. Quick movements trigger the flight response that makes this species challenging to handle. Use catch cups (guiding the spider into a container and covering with a lid) rather than direct hand contact whenever possible. This approach is less stressful for both the spider and keeper.

If direct handling must occur, allow the tarantula to walk onto a flat, open palm rather than grasping or pinching the body. Support the spider's weight fully and maintain close proximity to a soft surface in case of sudden movement. Never handle over hard floors or elevated surfaces where a fall could cause injury. Handle only calm, settled individuals and cease immediately if the spider shows stress signs like rapid movement, raising front legs, or rubbing the abdomen.

Routine care requires minimal direct interaction with the spider. Feeding can be accomplished by dropping prey into the enclosure. Water dish maintenance typically requires only reaching in with the dish, which can be done without disturbing a spider in its burrow. Spot cleaning with long tweezers or forceps keeps hands at safe distance. Complete substrate changes and rehousing represent the primary occasions requiring direct spider management.

Never handle during the pre-molt or post-molt period. Pre-molt tarantulas are stressed and more likely to respond defensively. Post-molt specimens have soft, vulnerable exoskeletons easily damaged by handling. Wait at least a week after molting before any handling attempts, and even then, handle only if truly necessary.

The Costa Rican Zebra Tarantula makes an excellent choice for keepers seeking a visually striking species with manageable care requirements. Its bold leg striping creates immediate visual impact, while its hardy constitution forgives minor husbandry mistakes that might stress more delicate species. The combination makes it suitable for beginners, though its skittish nature means it's better suited to those comfortable with a display animal rather than a handling subject.

The species' secretive, burrowing nature requires appropriate expectations. Keepers should appreciate the natural behavior rather than expecting constant visibility. Long periods may pass with the spider hidden in its burrow, emerging only briefly for feeding or nighttime activity. Those seeking a constantly visible pet should consider other species, while those who enjoy the anticipation of occasional sightings will find this species rewarding.

The dramatic lifespan difference between sexes warrants consideration. Female Costa Rican Zebra Tarantulas may live 20-35 years, representing a commitment spanning decades. This longevity rivals or exceeds many traditional pets like dogs and cats. Potential keepers should honestly assess their ability to provide appropriate care over this entire lifespan, including through life changes like moves, career changes, and family additions. Males live much shorter lives (5-7 years), which may suit keepers uncertain about multi-decade commitments.

Space requirements are modest, with adult enclosures fitting easily in most living situations. The species' tolerance of room temperature conditions eliminates the need for heating equipment in most climates. Ongoing costs for food are minimal. The combination of affordable initial setup and low maintenance costs makes the species accessible to most interested keepers.

Captive breeding has become increasingly important for this species, as wild collection impacts natural populations. Sourcing captive-bred specimens supports sustainable hobby practices while typically providing healthier, better-acclimated animals. Many reputable breeders produce this species regularly, making captive-bred individuals increasingly available.

The species' combination of beauty, hardiness, and moderate care requirements has made it a hobby staple. While not as flashy or active as some species, the Costa Rican Zebra Tarantula rewards patient keepers with occasional glimpses of its striking appearance and the satisfaction of maintaining a long-lived, fascinating invertebrate.