Trivia question for Apr-10-2011

Carter had no problem picking today’s trivia and he feels confident he has made it difficult enough to stump everyone… let’s see how he does.  These fish are generally found amongst rocks or algae at a depth of 66–200 ft.  Growing up to 5.2 ft long, they have a robust body with a broad, rounded head and two dorsal fins placed far back.

Primarily nocturnal, these guys spend the day inside small holes in rocks and swim into deeper water at night to hunt. Sometimes two will squeeze into the same hole, and several individuals will seek out refuges within the same local area. In one tracking study, a single immature species was observed to use five different refuges in succession over a period of 168 days, consistently returning to each one over a number of days before moving on.

So here are Carter’s questions: What are these fish?  Some of these fish have a small hole, or spiracle, behind each eye, tell us what the hole is used for?  Also, tell us if during birth, these guys lay eggs, or deliver live babies?

Good Luck 😉

Answer:

Wow, Carter is on a role.  No correct answer again tonight.  The fish we featured is the The nursehound, also known as the large-spotted dogfish, greater spotted dogfish, or bull huss, is a species of catshark found in the northeastern Atlantic Ocean.  (So is it a Catshark or a Dogfish?  Who came up with these names anyway?)

The small hole just behind some of these species eyes is actually a breathing hole which is part of their gills.  Adults move into shallow water in the spring or early summer, and mate only at night. They lay eggs which are deposited in the shallows from March to October. Although a single female produces 77–109 oocytes per year, not all of these are ovulated and estimates of the actual number of eggs laid range from 9 to 41. The eggs mature and are released two at a time, one from each oviduct. Each egg is enclosed in a thick, dark brown case measuring 3.9–5.1-in long and 1.4-in wide. There are tendrils at the four corners, that allow the female to secure the egg cases to bunches of seaweed.  Here is more on these little sharks:  Nursehound/Dogfish

Thanks for playing along 😉