| BORER | Destructive worm, mollusc or insect |
| SLUG | Land mollusc or limax studied in limacology; a draught or gulp of liquor; a line of type in Linotype printing; or, a counterfeit coin used in a slot machine (4) |
| SPAT | A large drop of rain; a petty quarrel; a short cloth gaiter; a drag-reducing fairing or pant for an aircraft wheel; a baby mussel, oyster or other mollusc; or, said shellfish collectively (4) |
| CLAM | Old wooden footbridge in the form of a suspended log; mollusc or "vongola"; or, a reticent person (4) |
| BIVALVE | Mollusc or bird losing half a regulator |
| ORMER | Mollusc, or merely part of it? |
| SCORPION | Some mollusc, or pioneer predator? (8) |
| NAUTILUS | Mollusc, or Captain Nemo's vessel (8) |
| RAZORSHELL | Sharp mollusc or its protective cover cuts he will complete (5,5) |
| SCORPIO | Some mollusc or pioneer born towards the end of the year (7) |
| PAUA | New Zealand sea mollusc or its shell used in jewellery |
| CONCHOLOGIST | A person who collects or studies molluscs or seashells (12) |
| CORMORANT | Origin of 17 or insect or bird (9) |
| PESTS | Troublesome or destructive animals or insects (5) |
| SCALLOPS | From the Old French for "shells", "clams" with fan-shaped shucks; rows of decorative curves resembling said molluscs; or, coquille dishes (8) |
| OYSTERS | Pearl-forming molluscs or "huitres", referred to by Pistol in The Merry Wives of Windsor (7) |
| ANTI | Opposed to insect being skinned (or insect being skinned twice) |
| EARWIG | Listen to bug or insect (6) |
| VERMIN | Animal or insect pests (6) |
| TIGERMOTH | Rock to hit sheltering bug or insect (5,4) |
