Toxicity of Commercial Neem Extract to Earthworms (Pheretima peguana)

Table 4

Radial thickness of epidermis, body wall, and intestinal epithelium of Pheretima peguana exposed to commercial neem extract (NEEM) and Cd for 48 h.

Agent	Concentrations (𝜇g cm^−2)	𝑛 *	Radial thickness (μm)
			Epidermis	Body wall	Intestinal epithelium
Negative control	0	30	32.02 ± 0.36^b	309.67 ± 1.54^b	19.19 ± 0.50^a
Positive control (Cd)	0.01	30	35.10 ± 0.22^c	303.89 ± 1.15^b	63.97 ± 1.66^c
NEEM	0.39	30	30.97 ± 0.33^b	300.11 ± 9.26^b	23.52 ± 0.53^a
	0.78	30	30.18 ± 70.69^b	297.53 ± 4.26^ab	25.38 ± 0.97^a
	1.57	30	29.98 ± 0.47^b	293.57 ± 6.65^ab	26.52 ± 0.84^a
	2.35	30	29.19 ± 0.84^b	278.64 ± 1.54^a	48.05 ± 2.01^b
	3.13	30	26.08 ± 0.50^a	277.28 ± 5.26^a	55.58 ± 3.83^b

Within a column, data (mean ± SEM) marked with the same letter are not significantly (𝑃>.05) different from each other.
* 𝑛=30 is based on an average of six areas selected from each region, 10 serial sections per earthworm, from three earthworms per treatment.