Out of the 94 surviving migrants about 20 managed to reach the shore while the others were rescued by Italian coastguard boats.
D'Arrigo described the rescued migrants as Syrians and some Egyptians and "mostly young adults" who were currently being identified by authorities.
More than half are minors. The spokesman added that a pregnant woman and a severely dehydrated child had been taken to hospital out of precaution.
The prosecutor in Catania, Giovanni Salvi, has opened an investigation into clandestine immigration and possible homicide.
He explained that after the 18-metre-long (59-feet) fishing boat ran aground about 15 metres from the beach, the migrants thought they could walk ashore "but they drowned because unexpectedly the water became deep".
Authorities do not know at this point where the boat set off from but said it had been en route for a week.
Dario Monteforte, owner of the Lido Verde resort which had alerted authorities, told Sky TG24 television that he "saw a crowd of youths on the beach running toward the road".
Monteforte, visibly shaken by the sight of body bags on the beach, has closed his establishment for the weekend.
"Something has to be done. This is really an unending tragedy," he said of the plight of thousands of clandestine migrants in rickety boats who seek to reach Italian shores each year.
"We have to stop these merchants of death," said Italian Interior Minister Angelino Alfano, urging Brussels to work more closely with Italy on the migrant issue.
His comments were echoed by Italy's first black minister, Italian-Congolese Cecile Kyenge, in charge of integration, who also called for stronger action by the European Union.
She said it was necessary "to put strong pressure on Europe to implement real policies that prevent our country from being alone in the face of such dramatic situations."
Also on Saturday other Mediterranean rim countries, Spain and Morocco, had to come to the rescue of nearly 90 would-be immigrants travelling in makeshift boats.
According to D'Arrigo, it was "totally unusual" in Sicily for migrants to land on a beach in Catania as "normally they arrive further south in the region of Syracuse", or else at the extreme southern point of the main Sicilian island, or Lampedusa island.
Another group of about 100 migrants, mostly Syrian families, were rescued overnight Wednesday off the coast of Calabria on the Italian mainland.
They had left Syria two weeks earlier and had to change boats several times before being left adrift aboard an 11-metre (35-foot) vessel.
The conflict in Syria has killed more than 100,000 people since it erupted in March 2011 and millions more have been displaced or have fled the country, according to the United Nations.
Improved weather and calmer waters have seen a spike in boat people arrivals in Italy in recent days.
But shipwrecks are frequent because the boats are often old and overloaded. Human traffickers regularly abandon their passengers when Italian or Maltese coastguards spot them.