Science Teacher's “Fish Biology and Anatomy” Lesson

An all-night fishing trip to the Wilmington Canyon on the edge of the continental shelf, 105 miles from his home port of Manasquan and 65 miles off the coast of Delaware, yielded a successful catch for science teacher John Shipley and a lesson in fish anatomy for the students in his Marine Biology classes.

Some of the students were a bit squeamish about the yellowfin tuna laid out for dissection when they arrived at class Tuesday morning, October 11. But once they grew accustomed to the shine and the slime of the 25 lb fish, all but a few moved in close for good view of Shipley’s informative anatomy lesson.

Beginning the lesson with the itinerary of the fishing trip, Shipley explained that real-time satellite imagery of the sea surface temperatures, coupled with recent fishing reports indicated that a long trip would be necessary. Their first stop, Spencer Canyon, proved too busy with approximately 100 boats fishing at that spot. He and his friends then headed further south-east to where there was not as much competition.  They settled on a weed line in 800 fathoms (4800 ft.) well off of the continental shelf.

Using chunks of butterfish as bait, Shipley and company brought in 10 tuna, most of which were in the 50lb – 60lb class as well as several Mahi-Mahi.  He brought the two smallest tunas to school and one Mahi-Mahi, packed in ice, to show to his two marine biology classes.

A number of the teachers at Summit High School also benefited from Shipley’s fishing trip. After the dissection of the tunas, he gave the steaks to some of his co-workers – with cooking instructions. (Grill or sear in a very hot pan, not too long, just lightly brown on both sides, rare in the center. Great served with wasabi.)

During the lesson, which was supplemented by a handout on “Fish Biology and Anatomy,” students saw the retractable dorsal fin of the tuna and other features which make the tuna a formidable predator; the heart, which is large for a fish, located in the fish’s head between the gills; and the intestines, which drew the most (negative) reactions from the students.  Students also learned that tunas and some other highly predatory pelagic species have warmer blood than the surrounding water, to keep their muscles moving faster than their prey species’.

Shipley did not speak highly of the intelligence of the tuna, which, he says, has a brain the size of half a pea. “I’ve been fishing when the boat was surrounded by both dolphin and tuna,” he recalled. “The dolphin are jumping and playing with the bait, never biting, but the tuna tend to go right for the hook.”

An avid and experienced sports fisherman, Shipley said that because his family is so accustomed to dining on freshly caught fish, they never buy fish in the store.  It was remarkable that with so much fish cut up on the table, there was no odor in the classroom.  Said Shipley, “Truly fresh fish doesn’t smell like fish at all."