A new species of Paraheligmonella (Nematoda, Heligmonellidae), parasite of Sylvilagus floridanus (Leporidae) from Costa Rica

Abstract

PARAHELIGMONELLA LAMOTHEI N. SP. (HELIGMONELLIDAE: HELIGMONELLINAE) IS DESCRIBED FROM THE SMALL INTESTINE OF A COTTONTAIL, SYLVILAGUS FL ORIDANUS (ALLEN, 1890) (LEPORIDAE), FROM COSTA RICA. NEW MORPHOLOGICAL DATA ON THE SYNLOPHE AND CAUDAL BURSA OF PARAHELIGMONELLA ROMEROLAGI (GIBBONS AND KUMAR, 1980), THE MOST SIMILAR SPECIES, ARE ALSO PROVIDED. THE NEW SPECIES DIFFERS FROM P. ROMEROLAGI, PARASITIC OF ROMEROLAGUS DIAZI (FERRARI-PÉREZ, 1893) FROM MEXICO, MAINLY BY THE CHARACTERS OF THE CAUDAL BURSA AND THE SYNLOPHE OF THE FEMALE WITHIN THE POSTERIOR REGION OF BODY. MALES OF P. LAMOTHEI N. SP. POSSESS A CAUDAL BURSA NOT BELL-SHAPED, WITH A PATTERN OF TYPE 2-2-1 FOR RIGHT LOBE AND 2-3 WITH A TENDENCY TO TYPE 2-2-1 FOR LEFT LOBE, WHEREAS MALES OF P. ROMEROLAGI POSSESS A BELL-SHAPED CAUDAL BURSA, WITH A PATTERN OF TYPE 2-2-1 WITH A TENDENCY TO TYPE 4-1 FOR BOTH LOBES. IN P. LAMOTHEI N. SP. RAYS 3 ARE SLIGHTLY LONGER THAN RAYS 2 AND THE GENITAL CONE IS POORLY DEVELOPED, WHEREAS IN P. ROMEROLAGI RAYS 3 ARE MUCH LONGER THAN RAYS 2 AND THE GENITAL CONE IS LARGE AND BULBOUS. FEMALES OF P. LAMOTHEI N. SP. POSSESS, AT OVEJECTOR LEVEL, VENTRAL AND LATERO-VENTRAL RIDGES HYPERTROPHIED AND DORSAL RIDGES REDUCED, WHEREAS AT THE SAME LEVEL, FEMALES OF P. ROMEROLAGI POSSESS LATERAL RIDGES HYPERTROPHIED AND DORSAL AND VENTRAL RIDGES REDUCED. ADDITIONALLY, HYPERTROPHIED CUTICULAR RIDGES POSTERIOR TO THE VULVA ARE PRESENT IN P. LAMOTHEI N. SP., BUT ABSENT IN P. ROMEROLAGI.