"radula-like spine covered" Spine-covered. Otherwise, one might confuse "spine" for "backbone".
"blood containing haemoglobin": Haemoglobin-containing blood, or, as an option that's not so good, "blood, containing haemoglobin". Strictly speaking, "haemoglobin-based blood" is a little more specific and natural-sounding.
"specialize each in their own" sounds redundant.
"growth, others" You surely meant to insert "while" or "and" before "others".
"startled" Startle.
It needs a scientific name. If you want to go with something basic, "Floraverm spp." or "Floravermus spp" will work, since its common name sounds pretty scientific anyway.
The paper background should be decreased in prominence: it's grainy and the lighting is uneven. I also recommend making the lineart look sharper with some quick image processing, although that isn't required.
Since it's a genus group, and a somewhat specialized one at that compared to most species, I recommend adding a little more detail. What's the species distribution like for various kinds of flora? Are there particular varieties of flora, such as less digestible kinds, they don't eat? Are the specific types of tissue listed the only ones they eat? (Say, not eating thorns, prickles, hard tubers, seeds, inner bark or outer bark) Are they deterred by particular kinds of compounds or flavors? Are they active at specific times? Are they, like their ancestors, rarely found in aquatic biomes? How much detritus do they eat compared to fresh growth? (In comparison, roly-polies prefer decaying matter to seedlings, while some snail species prefer decomposing matter to fresh plants)