Squamata

Zamani, Alireza, West, Rick C. & Lamar, William W., 2024, An extensive review of mutualistic and similar ecological associations involving tarantulas (Araneae: Theraphosidae), with a new hypothesis on the evolution of their hirsuteness, Journal of Natural History 58 (29 - 32), pp. 1107-1143 : 1121

Snakes ( Squamata: Serpentes )

Herein, we report three potential cases of mutualistic interactions involving tarantulas sharing their retreats with snakes ( Table 3 ). The first case was observed in Guerrero State of Mexico by the second author. While turning over large angular rocks lying on the ground in search of theraphosids, one rock was turned to expose the burrow of a large female Brachypelma boehmei Schmidt and Klaas, 1993 ( Theraphosinae ) standing mere centimetres away from a coiled Michoacán ground snake, Sonora michoacanensis (Duges, 1884) ( Colubridae ). No predation attempt was made by the tarantula on the snake. While preparing the camera to record this event, the exposed snake, approximately 30 cm in length, started to burrow into the soft soil surrounding the spider’s burrow ( Figure 6F ).

The second and third observations are sourced from iNaturalist. One of them details an unidentified species of Phoneyusa Karsch, 1884 (Eumenophorinae) cohabiting with a ‘small blue snake’ in Banalia, Democratic Republic of the Congo. The other, from Texas, USA, describes Aphonopelma armada ( Theraphosinae ) cohabiting with a Texas blind snake, Rena dulcis Baird and Girard, 1853 ( Leptotyphlopidae ). Further observations and research are needed to better understand the dynamics and frequency of these cohabitations.

Additionally, we report observations of tarantulas actively removing snakes from the vicinity of their burrows. In November 1993, RCW and WWL attempted to document a predation interaction between a large female Megaphobema velvetosoma and a Catesby’s snail-eater snake, Dipsas catesbyi (Sentzen, 1796) ( Colubridae ), for a wildlife photographer near the village of Nueve de Octubre on the Río Marañón, Loreto, Peru. The (Continued) (Continued) snake was released and approached the tarantula, which was lying in wait at the entrance of its ground retreat. The tarantula grabbed the snake with its chelicerae, causing the snake to expel an odorous liquid musk from its anal glands. The tarantula transported the uninjured snake approximately 50 cm away from the retreat entrance and then released it before returning to its retreat. This behaviour was repeated, with the tarantula again capturing, carrying, and releasing the snake, which appeared unharmed. To determine whether this behaviour was specific to the individual tarantula, a similar predation attempt was conducted with a different adult female M. velvetosoma , located earlier by a guide. The observed behaviour was consistent with the previous event, with the tarantula immediately grasping the snake, carrying it to the edge of the clearing in front of its ground retreat, and releasing it unharmed. We hypothesise that the odorous liquid expelled by the snake may render it unpalatable to these tarantulas, thereby providing a protective mechanism for the snake. Alternatively, the snake may simply not have represented suitable prey and the spider’s behaviour therefore involved mere removal from its burrow.

Figures

Figure 6. Associations between tarantulas and whip spiders, a harvestman and a snake. A. Sericopelma sp. sharing its retreat with an unidentified whip spider (marked with an arrow), La Chorrera, Panama. B. Megaphobema velvetosoma sharing its retreat with an unidentified whip spider (marked with an arrow), Yasuní National Park, Ecuador. C. Sericopelma sp. and Paraphrynus laevifrons, Santa María de Dota, San José Province, Costa Rica. D. Phormictopus cautus sharing its burrow with an unidentified whip spider, Vinales, Pinar del Río Province, Cuba. E. Sericopelma sp. sharing its retreat with an unidentified harvestman (marked with an arrow), Upala, Alajuela Province, Costa Rica. F. Brachypelma boehmei sharing its retreat with Sonora michoacanensis (marked with an arrow), Guerrero State, Mexico. Photo credits: John G. Phillips (A), Aidan Craner (B), Johnson Jou (C), José Garrido (D), Dan MacNeal (E), and Rick C. West (F).