Tarantulas are recognized for their size and hairy appearance. While adult tarantulas are familiar, the journey from a tiny hatchling to a mature spider involves remarkable transformations. These young tarantulas, commonly referred to as spiderlings or “slings,” undergo significant changes in appearance as they grow, distinguishing them visually from their adult counterparts.
Appearance of Newborn Spiderlings
Immediately after hatching, tarantula spiderlings are small, often compared to the size of a grain of rice or a small pea, typically measuring only a few millimeters in leg span. Their initial coloration is pale, appearing translucent or milky white, lacking the vibrant patterns and deep hues of adult tarantulas.
The body shape of a newborn spiderling is more compact and “blob-like” than that of a mature tarantula, with a proportionally larger and rounder abdomen. Their leg segments are less defined, appearing somewhat stubby compared to the elongated limbs of adults. While they are covered in fine, downy fuzz, this differs from the dense, bristly hairs that characterize older tarantulas.
Growth and Molting Transformations
Tarantulas grow by molting, or ecdysis, shedding their rigid outer skeleton, known as the exoskeleton. This shedding is necessary because the exoskeleton does not grow, so the tarantula must periodically replace it to accommodate its increasing size. Young spiderlings molt frequently to facilitate rapid growth.
Each molt brings noticeable changes in the spiderling’s appearance. Immediately after shedding its old skin, the tarantula’s new exoskeleton is soft and vulnerable, gradually hardening over several days. With each successive molt, the spiderling increases in size, and its body proportions begin to shift, with legs becoming more elongated and defined. Coloration also starts to intensify, and the distinct patterns characteristic of its species may begin to emerge, though they are usually duller than adult colors.
Key Differences from Adult Tarantulas
The most obvious distinction between a spiderling and an adult tarantula is size. Adult tarantulas can range in leg span from 2 to 10 inches, making them larger than their millimeter-sized hatchlings. Body proportions also differ, with adults possessing more robust, elongated legs and a more clearly segmented cephalothorax and abdomen, whereas spiderlings have a more compact, less defined form.
Coloration provides another differentiator; adult tarantulas display richer, more vibrant colors and intricate patterns specific to their species. In contrast, spiderlings are monochromatic or have muted tones, with their full adult coloration developing over multiple molts. While both have hairs, adult tarantulas develop dense hairs on their abdomen, which are absent or very fine on spiderlings. Sexual dimorphism, where males and females exhibit distinct size, leg length, or coloration differences, becomes apparent only in adult tarantulas, a characteristic not visible in spiderlings.