Evidence for specificity of Steganoderma formosum for its second intermediate host in the Northwest Atlantic

• Published in: Journal of Helminthology
• Main Author: Marcogliese, D.J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1996
• Subjects: Canada; Pacific; Northeast Atlantic; Northwest Atlantic
• Online Access: http://dx.doi.org/10.1017/s0022149x00015431; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022149X00015431

Abstract Metacercariae of Steganoderma formosum Stafford, 1904 infected 17 of 358 Acadian hermit crabs ( Pagurus acadianus ) on the Scotian Shelf east of Nova Scotia, Canada, in the Northwest Atlantic Ocean in 1989, 1990 and 1995. Overall prevalence and abundance in P. acadianus on the Scotian Shelf were 5% and 0.4 metacercariae per crab, with a maximum intensity of 56. The highest prevalence (34%) and abundance (2.9) were recorded in the winter of 1989. All infected hermit crabs were greater than 9 mm in cephalothorax length. The parasite was not found in Acadian hermit crabs (n = 74) from Georges Bank, nor in any hairy hermit crabs ( P. arcuatus and P. pubescens ) on the Scotian Shelf (n = 808), on Georges Bank (n = 14), or in the northern Gulf of St. Lawrence (n = 87). A single sand shrimp ( Crangon septemspinosa ) of 1254 collected from the Scotian Shelf in 1989 and 1990 was infected with a metacercaria of S. formosum . None of 421 pink shrimps ( Pandalus spp.) collected from the Scotian Shelf in 1989 and 1995 was infected. Male and female reproductive systems were well developed and spermatozoa were observed in the seminal receptacles of most parasites, suggesting that these metacercariae are progenetic. The distribution of the parasite among potential intermediate hosts suggests that S. formosum demonstrates greater specificity for its second intermediate host in the Northwest Atlantic than it does in the Pacific or in the Northeast Atlantic oceans.