Titan Isopods (Porcellio hoffmannseggii)

Most isopods reward a hand lens; the Titan you can watch from the sofa. Porcellio hoffmannseggii is one of the largest terrestrial isopods in the hobby, reaching up to around 4 cm, a Spanish cliff-dweller so substantial that its whole appeal is scale rather than colour. It wears a clean grey with crisp white skirting along each segment edge, an understated, almost dignified look that lets the sheer size do the talking. For a keeper who wants an isopod with real physical presence, few species deliver it as plainly as this one.

It belongs to the giant Spanish Porcellio, the same bracket as the vivid orange Porcellio magnificus, the yellow-marked Ornatus and the flat, flared Expansus, but where magnificus brings colour, the Titan brings size and a calm, grey solidity. It is a rare species and a serious step up from beginner Porcellio, though not a difficult one: coming from dry Mediterranean cliffs, it actually prefers the drier, airier conditions most UK homes provide over the humid setups tropical isopods demand. One thing to plan for is the males, which are territorial and will chase off rivals, so give a colony space and cover to spread out.

Moisture is the point to get right, and it runs opposite to the tropical instinct. The Titan wants a dry, well-ventilated enclosure with a single damp corner rather than an all-over humid box: keep the bulk of the tub on the drier side, mist one corner to give the colony somewhere moist to retreat, and run strong cross-ventilation. Normal room temperature suits it, and it takes the drier end of Spanish-Porcellio conditions without complaint. Around 20 to 26°C suits it, and like most big isopods it is slow-growing and long-lived, taking its time to reach that full 4 cm.

Give them plenty of floor space in a well-ventilated tub, then a free-draining substrate: a base of flake soil, rotted hardwood and topsoil with extra drainage worked in, kept mostly dry with that one moist corner. Leave a plain coco-coir base out, as it holds far too much water for a dry-habitat animal. Lay cork bark and rock or slate across the surface for the cover and territory the big Porcellio use, and make calcium freely available through cuttlebone, crushed limestone or oyster shell, because a large isopod moulting a large shell needs plenty of it.

Feeding leans towards protein more than the pill woodlice do. Leaf litter and rotting wood are the base, but keep a protein source going, fish flake, dried shrimp or a proper isopod protein, a couple of times a week, alongside soft veg such as squash, carrot and sweet potato. An underfed colony of big, fast Porcellio can turn on its own moulting members, so treat protein as part of the setup. There is more on the group in our guide to the different types of Porcellio.

Breeding is measured rather than rapid, as with the giant Porcellio generally: a stable, correctly dry setup with good calcium and space will see females carry young and release live miniatures, building the colony gradually. Browse the wider Porcellio collection to see where the Titan sits among its relatives. Every order is captive-bred, packed with care in a double-walled box around a ventilated tub of damp sphagnum, posted Monday to Thursday by tracked next-day Royal Mail with a live-arrival guarantee.