A blindsnake that decapitates its termite prey

Abstract

Almost all snakes swallow their prey whole. However, a few species are known as exceptions. Two species of Asian crab‐eating snakes tear off crab legs and ingest them one at a time to eat prey that is otherwise too large. Two species of leptotyphlopid blindsnakes break off the head of termites or suck abdominal contents of termites, discarding remains of termites. Here, we show that a typhlopid blindsnake Indotyphlops braminus decapitates its termite prey and consumes only the thorax and abdomen. In our feeding trials, I. braminus decapitated a median of 47% of termites they eat, while swallowing the remaining termites whole. Decapitation did not affect ingestion speed, and therefore, it is unlikely that decapitation assists for fast ingestion. Ingested termite heads often remain undigested in the feces, implying that the decapitation functions to remove an indigestible part of termites. Decapitation might also be related to circumvention of chemical defenses of termites because termite heads often contain toxic compounds. These observations showed unusual feeding behavior used by a basal snake, which could be associated with removal of indigestible and/or toxic parts of prey items.

Toxin-resistant isoforms of Na+/K+-ATPase in snakes do not closely track dietary specialization on toads

“…), fishes (Nerodia rhombifer, Helicops angulatus), and mammals (Crotalus atrox, Agkistrodon contortrix; electronic supplementary material, table S1). It is possible that the same mutation protects a few of these taxa against other toxins that exert yet unknown pharmacological effects (as in some molluscs [41] and other invertebrates [42][43][44][45][46]). However, most non-toad-eating species that possess the resistance mutations appear not to derive any benefit nor incur a substantial cost from the mutated form rspb.royalsocietypublishing.org Proc.…”

“…Alternatively, resistance may have evolved independently in scolecophidians, nearly all of which specialize on a diet of social insects, either ants or termites [8]. Ants are defended by a diverse array of alkaloids [42,43], and some termites possess terpene toxins [43][44][45][46], although the diversity of toxins in the early life-history stages on which scolecophidians largely feed is not well known. The pharmacological effects of most of ant and termite compounds are also poorly understood, and thus it is uncertain whether the same mutations to Na þ /K þ -ATPase that confer resistance to BDs would protect against those prey.…”

Mandibular sawing in a snail-eating snake

“…Most of > 3,700 species of snakes swallow their prey whole, and prey-breaking behaviours are known only from a few species that feed either on crabs 20 – 23 or termites 24 – 26 , which may be relatively easily broken into segments. These snakes grasp their arthropod prey with their jaws and break it apart usually using the movements of the head or the trunk.…”

Predators as drivers of insect defenses

“…Blind snakes specialize in eating soil insects such as termites and ants (Cundall & Greene 2000). However, the blind snake Indotyphlops braminus (Daudin) avoids eating the heads of termites as those are where defensive chemicals are produced in the head (Mizuno & Kojima 2015).…”