Fish parasites

Twelve specimens of Heterobranchus longifilis sampled from the River Boumba were examined for their monogenean gill parasites. Quadriacanthus longifilisi N'Douba,Lambert & Euzet 1999 and Q. thysi N'Douba, Lambert & Euzet 1999 are newly recorded in the studied locality. Three new species have also been described: Q. tricorniculai n. sp., Q. triunguisin. sp., and Q. ndoubai n. sp. Quadriacanthus tricorniculai and Q. triunguisi are characterized by the unique morphology of their accessory pieces, which end in a three-head hydrashapedstructure, with tentacles being longer in Q. tricorniculai; proximal extremity of accessorypiece is stronger for Q. triunguisi, while Q. ndoubai is distinguished by the size of its male copulatory organ (larger than 80 mu m) and the fork shaped distal extremity of the accessory piece of the male copulatory complex. The variability of monogenean species richness of Hetero-branchus longifilis between Ivory Coast and Cameroon is discussed

Influence of preservative and mounting media on the size and shape of monogenean sclerites

Based on Cichlidogyrus sp. (Monogenea, Ancyrocephalidae) specimens from Hemichromis sp. hosts, we tested the influence of different methods to fix/preserve samples/specimens [frozen material, alcohol or formalin preserved, museum process for fish preservation (fixed in formalin and preserved in alcohol)] and different media used to mount the slides [tap water, glycerin ammonium picrate (GAP), Hoyer's one (HM)] on the size/shape of sclerotized parts of monogenean specimens. The results show that the use of HM significantly increases the size of haptoral sclerites [marginal hooks I, II, IV, V, and VI; dorsal bar length, width, distance between auricles and auricle length, ventral bar length and width], and changes their shape [angle opening between shaft and guard (outer and inner roots) in both ventral and dorsal anchors, ventral bar much wider, dorsal one less curved]. This influence seems to be reduced when specimens/samples are fixed in formalin. The systematics of Monogenea being based on the size and shape of their sclerotized parts, to prevent misidentifications or description of invalid new species, we recommend the use of GAP as mounting medium; Hoyer's one should be restricted to monogenean specimens fixed for a long time which are more shrunken