The House passed a $10.1 billion public works spending bill yesterday after bowing briefly to fiscal restraint and sinking a fish-hook into the pesky snail darter.

Ignoring President Carter's threat of a veto, the House voted 263 to 59 -- well beyond the margin needed to override a veto -- to pass the controversial "pork barrel" appropriation.

Before the final vote, the House:

Approved an amendment providing money to complete the Tellico Dam in Tennessee, home of the tiny snail darter fish, in a step intended to offset a Supreme Court decision Thursday against the project.

Reject a move to cut 5 percent from the bill's original cost, but agreed to trim it 2 percent -- $206 million -- across the board as a response to perceived public demands for government spending restraint.

Approved without question $157.5 million for the Clinch River breeder reactor demonstration project, one opposed by administration.

The bill contains fiscal 1979 operating funds for federal water resources agencies, the departments of Interior and Energy and some independent agencies.

The most debated section, however, was the water project portion, which in its final form contained eight projects that President Carter sought to stop, plus 11 more than he wanted added.

Floor discussion was minimal, but the biggest noise yesterday came after adoption of an amendment by Rep. John Duncan (R-Tenn.) to spend $1.8 million to complete the nearly finished Tellico Dam.

The Supreme Court had ruled Thursday that the dam could not be finished by the Tennessee valley authority because its reservoir would destroy the only known habitat of the snail darter.

The snail darter is protected by the Endangered Species Act. The court held that TVA had not followed the act in proceeding with the Tellico project on the Little Tennessee River.

Duncan insisted afterward that approval of his amendment -- if the Senate accepts it -- "takes care of the Supreme Court objection -- I think the project will be completed."

Others, however, took issue with Duncan. Reps. John Dingell (D-Minch.) and Richard Ottinger (D-N.Y.) had been prepared to challenge Duncan on th floor, but did not when they concluded that his amendment did not answer the Supreme Court's objection.

Both congressment said that Duncan's language in no way amends the Endangered Species Act, which, as interpreted by high court, prevents TVA from completing the dam.

Brent Blackwelder of the Environmental Policy Center, a major lobbyist against many of the flood control projects in the bill, agreed that the Duncan amendment would not effect Tellico.

He said House passage of the water resources portion of the bill was "reckless and irresponsible -- a flagrant example of bad faith. If President Carter doesn't veto this bill, Congress will see him as a real powder-puff."

Friends of the Earth, another environmental group, said the Duncan amendment was a "face-saving device" that would not "to the best of our knowledge, impact in any way on the snail darter or yesterday's decision by the Supreme Court."

Duncan also has pending before the House a bill that would specifically exempt Tellico from the requirements of the Endangered Species Act, but it has not moved from committee.