The biochemical defenses of Pomacea snail eggs are effective against mealworm beetles.

Area of Science:

• * Ecotoxicology and invertebrate biology
• * Biochemistry and molecular defense mechanisms

Background:

• * Pomacea snail eggs possess potent anti-predatory defenses in their perivitelline fluid (PVF).
• * Clade-specific toxins include enterotoxic lectins (Bridgesii clade) and neuro-enterotoxin perivitellin-2 (PV2) (Canaliculata clade).
• * Vertebrate toxicity of Pomacea PVF is known, but invertebrate effects are unexplored.

Purpose of the Study:

• * To investigate the toxicity of Pomacea canaliculata and Pomacea scalaris egg PVF on Tenebrio molitor larvae.
• * To assess the impact of PVF on larval mortality, feeding behavior, life cycle, reproduction, and histology.

Main Methods:

• * Administered PVF from P. canaliculata and P. scalaris to mealworm larvae via injection and oral exposure.
• * Monitored mortality, feeding preference, life cycle progression, reproductive success, and performed histological analyses.
• * Determined lethal dose 50 (LD50) for P. canaliculata PVF (PcPV2).

Main Results:

• * P. canaliculata PVF caused 30% larval mortality upon injection, with an LD50 of 56.5 µg/g for PcPV2; P. scalaris PVF was non-lethal.
• * Oral PVF exposure induced midgut damage, fat body alterations, delayed pupation, and reduced fecundity in larvae.
• * Toxic proteins interacted with and crossed the larval peritrophic matrix; larvae exhibited feeding avoidance of P. scalaris PVF.

Conclusions:

• * Pomacea egg PVF exhibits toxicity towards invertebrates, demonstrating broad-spectrum anti-predator defenses.
• * These findings expand the known efficacy of snail biochemical defenses beyond vertebrate models.
• * PVF impacts invertebrate physiology and behavior, suggesting wider ecological implications.