The diamond-shaped ray surfaced near the 91st Street Fishing Pier around 1 p.m. Monday, drawing the attention of anglers and onlookers alike.

“You can tell that it is a manta ray by the distinctive white marking on the back and the cephalic fins near the mouth (the horn-like head fins in front of the mouth),” Eisenbach said.

“However, there have been multiple sightings of manta rays closer to shore off the coast of Galveston,” Eisenbach said. “While I wouldn’t say that it is very common to see manta rays this close to shore, it does happen sporadically.”

The most likely explanation for this week’s appearance is food.

“Large plankton blooms will attract manta rays and other planktivores,” Eisenbach said.

“These are plankton feeders, and plankton is much more abundant inshore than offshore,” he said.

In footage of the animal circulating online, Fisher said the manta appeared to be feeding.

“You can see the mouth is fully open,” he said. 

Roger Pace was among those who watched the ray glide near the pier. He estimated the animal had a wingspan of roughly 10 to 12 feet. Pace said many anglers initially mistook the ray for a shark and tried to catch it.

“It wasn’t until my son and I approached and told them it wasn’t a shark, and it was actually a manta ray, and that trying to catch such is not only illegal, but just wrong, and even then, many refused to give up on hooking this creature,” he told Chron.

“As fishermen of the Gulf Coast for more than 40 years, we could obviously tell it wasn’t a shark,” he said.

Manta rays are listed as threatened throughout their range, making it illegal in Texas to target, catch, harvest or keep them.

“They won’t/can’t bite a hook, but anglers will sometimes become entangled with them,” Fisher said. “They are too big for most conventional tackle to handle, and they break off.”

“I am still in awe of what we saw that day,” Pace said, “but just as much disappointed with my fellow fishermen who thought only of themselves in a time when we all should have just sat back and appreciated the opportunity to witness such beauty.”