Voters in New Orleans usually expect election campaigns to be dominated by unusual personalities - sometimes bordering on the unreal - and the field of 11 Democrats running in this year's mayoral race hasn't let anybody down.

For those who feel strongly such things, there is Rodney Fertel, the "Gorilla man." whose raison d'etre in the 1969 mayor's race was to acquire a great ape for the Audubon park Zoo. He got only 310 of the 176.736 votes cast, but this zoo eventually Fertet is promising to proect the gorillas from vandals and his campaign button is a photograph of King Kong with no further explanation.

For those easily moved by the Spirit, there is Thomas J. Garnier, who has spoken on a wide range of city problems, but insists that the main campaign issue is "whether you believe in God or not." He gets little debate.

Joel Aber has adopted some unique positions even for New Orleans, including a pledge to eliminate police brutality by firing the entire police force. But his most unusual stand - considering that it was made before an audience of Jewish women - was that the state of Israel should be disbanded.

Thomas Giraud is pushing citizens' band radio operators to form an anti-crime network, and his television appeal is backed by the patriotic strains of "America the Beautiful."

But out of the usual array of unusually diverse personalities, four serious contenders have emerged to provide the voters with the closest open primary in years and the promise of a bitterly contested runoff election on Nov. 12.

The primary on Saturday will have Ernest Morial, the first black major candidate in the city's history, competing for the black and liberal white vote with State Rep. de Lesseps S. (Toni) Morrison, the 33-year-old son of one of New Orleans' most popular reform mayors.

It will also include at the top of the pack a tough-talking, street-wise state senator. Nat Kiefer, who spends part of his time answering questions about several assault charges made against him after bare-knuckle fights, and Joseph V. DiRosa, an anti-establishment councilman from the Italian section of the French Quarter who has made a career of battling the city's public utility.

The candidates are seeking to succeed Moon Landrieu, the popular two-term mayor who cannot, by law, run for a third term.

Landrieu swept virtually unopposed into office in 1973 with a coalition of blacks, progressive conservatives and white ethnics, and his retirement has brought out of the dark corners of the Democratic clubhouses a stampede of aspiring candidates.

In the tradition of New Orleans politics, the contest is heating up in the final days to a rough and tumble affair, with vague allegations of corrupt connections and charges of below-the-belt campaign tactics.

Kiefer, in a debate this week before a businessmen's group, said, "I'm from the Ninth Ward, where campaign tricks originated. It's the brithplace of them, but I think the people of New Orleans are far too intellectual and astute to fall for the hate literature dropped at their doorstep."

He complained about phony midnight telephone calls to his constitutent's from his opponents, using his name, and about suggestive pamphlets obliquely referring his run-ins with the law and his admitted 1971 treatment in a hospital for a nervous disorder, which he attributed to a grueling legislative campaign.

But for his own part, Kiefer, who led the four top candidates by a small margin in a poll taken two weeks ago, generated a share of animostly from the Democratic establishment by his legislative committee investigation into the construction of the Superdome stadium, during which there were hints that some politicans had lined their pockets.

Landrieu was chairman of the stadium commission at the time, and many of his supporters have accused Kiefer of engaging in "McCarthyism" by alleging misconduct without proof. Several official state and city probes led to no indictments of anyone connected with the Superdone project.

Morial, who was the first black legislator elected in New Orleans and who now is an appeals court judge, is given a better-than-even chance of surviving the first primary for a try at becoming the city's first black mayor.

New Orleans is about 50 per cent black, and Morial in this primary round has concentrated his effort in the black neighborhoods, advertising his candidacy almost exclusively on ethnic radio.

If he survives Saturday, he is expected to pull heavily among white liberals in the Garden District north of the French Quarter and in the state university neighborhood.

Morial's record in politics is a seemingly endless series of firsts.

In 1954, he became the first black graduate of Louisiana State University law school: in 1967, he became the first black legislator in 1972, when he won a seat in the appeals court, he became the state's highest ranking elected black.

But he insists firmly he is not looking for any office higher than mayor, and suggested he might limited himself to one term.

Some Democratic official complain that Morial is short-tempered and occasionally abrasive, and they point to the time when a former candidate in endorsing an opponent, questioned Morial's ability to get along with people. Morial filed a $1 million law suit against the candidate which did little to enhance his image of compatibility.

How well Morial does Saturday depends on how solidly the black vote turns out for him, and how many black votes kiefer gets to go with his heavily middle-class support.

Knowledge Democratic politicians say also that to won, Morial will have to draw heavily among the estimated 40 per cent undecided voters.

Competing strongly for the same undecided bloc is Morrison, whose campaign has picked up strength in thefinal weeks and who is frequently mentioned as a pick for one of the two winning positions.

Morrison is the son of the late de Lesseps F. (Chep) Morrison, the reform candidate of the 1940s who was elected at age 34 and, after serving 16 years as mayor becamse ambassador to the Organization of American States.

The elder Morrison served as mayor before a city charter provision limiting the number of terms was enacted.

He was killed in a plane crash in Mexico in 1964.

Toni Morrison's campaign, while lackluster for weeks because of his low-key style and his lengthy discourses on issues, gained momentum recently with the endorsement of Landrieu and the backing of the city's major newspapers, the Times-Picayune and States-Item.

Attacking the high illiteracy rate - Louisiana ranks worst in the nation - Morrison has made an issue of rebuilding the city schools, even though the mayor has no direct control over the educational system.

He has also warned that other cities in the Sunbelt are beating New Orleans in the competition for industrial growth, and has promised to appoint a deputy mayor for economic development. Morrison also has seized on the crime issue, promising to accept personal responsibility for the police department.

But the other candidates have concentrated on the same issues, leading some of Morrison's supporters to worry whether his articulate progressivism will be overshadowed by the personality factor.