alligator-pear avocado avocado-pear butter-pear climacteric-fruit cultivar cut fertility-fruit firm flesh food fruit Fuerte-variety green guacamole healthy large-berry large-seed nutritious ovate pear-shaped perennials persea-americana ripe section smooth soft tree wrinkled alligator pear avocado pear black butter pear climacteric fruit egg-shaped fertility fruit Hass variety large berry large seed pebbled skin persea americana rough pebbled-skin kernel seed green-skinned hard unripened alligator-gar-fish ambush-predators animal aquarium aquatic atractosteus-spatula carnivores distinctive-snout elongated fish freshwater-fish gar habitat-destruction large largest-garfish piscivorous predator-fish primarily-piscivores primitive-fish river river-fish riverine Singapore Southern-United-States stalking-predators torpedo-shaped unusual voracious water zoo Hass-variety