Substrate

Substrate is an important part of a Geosesarma enclosure in the TGD Team's opinion and that Geosesarma appreciate the ability to burrow in the substrate and create territories. 

Substrate used can be any of the commonly used invertebrate hobby standards such as coco-fiber, peat moss, or topsoil, or customs or premade mixes. One of the The Geosesarma Database authors prefers to use a light weight mix using peat moss, crushed up leaves, bark and wood pieces, some horticultural perlite and some crushed charcoal either mixed in or above drainage layer, as it is also constructed for plant growth in addition to animal life. Whatever one uses it is important that it is free from fertilizers and chemical additives as those may have the ability to kills an invertebrate such as terrestrials crabs. 

Geosesarma in the wild are frequently found as adults and juveniles in dug out burrows on the walls of the banks of streams and using substrate that allows for the addition of burrow and digging seems to be appreciated by these crabs. One of the TGD authors constructed multiple premade starter burrows underneath very small pieces of cork-bark covered with moss in one of their vivarium and within the first day of adding the crabs they had immediately taken these burrows up as their home bases and have been observed deepening and altering these burrows overtime. 

One key aspect about substrate with regards to the successful keeping and breeding of Geosesarma is substrate depth and moisture. At all times one should give Geosesarma as ample substrate depth as possible for burrow formation and the establishment of separate burrow territories. Some species more so than others will extensively utilize the substrate depth to excavate underground cavities and tunnels. Substrate should also be evenly moist and never swampy or soaking wet, because of this it is advisable to always include a drainage layer that allows excess water to drain out. Light-Expanded-Clay-Aggregate or Leca is a common choice, and is lightweight. Other types of false bottoms include filter foam, stone pebbles, aquarium stone, etc. Whenever including a drainage layer do not forget to use a screen or mesh barrier in between the drainage layer material and the substrate. This author prefers carbon fiber window screen mesh, but other materials such as landscape barriers can also work. This author has found that the window screen offers the best drain-ability over the landscape cloth barriers. 

Yet to be tried in captivity by the TGD team is constructing a vivarium to match the high clay soil composition Geosesarma are documented burrowing into in the wild, but may be an option for substrate composition in a vivarium.  

Options for substrate: 

Cocofiber, Peatmoss, Topsoil, Clay, Custom Mixes, ABG mix, etc. 

Never use any soil specifcally made for plants such as "potting soil". Subsrtate must be free of chemical additives and fertilizers, always double check the ingredient labels!