Possible Clues:

• Aloof, distant in manner
• Rather not on the fish's
• Fishy? That's rather not on
• That's a bit unfriendly of Ray perhaps
• It's not friendly to switch his replacement
• Unapproachable
• Unfriendly old fellow and school member
• Piscine's a bit cool
• Belonging to school, perhaps, that's cold and unfriendly
• Cold -- quite rotten?