Gertrude The Gunnel
G
ertrude (lovingly named by last year’s summer student Kylie), is our resident Saddleback Gunnel. If you look carefully, you can see a series of “saddle” shapes all down the top of Gertrude’s spine as well as the vertical black stripe going around her face. Gertrude’s favourite food is fresh fish but she will also happily eat small crustaceans, worms, clams and fish eggs (not her own). Gertrude laid eggs in our tank again this season, under one of her favourite shells. She usually lays a ball of approximately 600 tiny white eggs mid- January. She will remain wrapped around the eggs, only leaving them occasionally to eat, and never going very far. When the eggs are close to hatching, the eyes are visible as tiny black dots in each egg. If the eggs survive, they will hatch in early to mid April. Unfortunately, this year’s eggs either hatched in the middle of the night or were eaten by another fish. The freshly hatched babies are only about 1mm long and completely clear, except for their eyes, so while some predators would have a hard
time seeing them, it’s possible for other fishes to find and eat the babies. When she’s not protecting a ball of eggs, Gertrude and other gunnels like to find tiny cracks between rocks & shells underneath seaweed to hide. These intertidal creatures can be found on most rocky shores in tiny puddles of water under rocks at low tide. The pictures you see are of Gertrude wrapped around a clutch of eggs, and of last year’s freshly hatched babies, taken through a microscope. Beach etiquette: Please be gentle with all creatures you find on the beach. The ocean is a hard place to live. If you turn a rock to look underneath, please turn it over and put it back exactly as you found it. The creatures that live under rocks need their homes to survive. Madeline Southern Aquarist/ Educator, Cowichan Estuary Nature Centre Cowichanestuary.ca
59
