Molecular and morphological evidence for the occurrence of Anisakis sp. A (Nematoda, Anisakidae) in the Blainville's beaked whale Mesoplodon densirostris

Abstract

Twenty-three adults (only one male) and two fourth-stage larvae of Anisakis, recovered from the stomach of a Blainville's beaked whale (Mesoplodon densirostris) stranded in Galicia (NW Spain), were studied morphologically and molecularly. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing studies carried out on the ribosomal DNA spacers and on the cox2 mitochondrial gene confirm that these nematodes belong to the taxon Anisakis sp. A, which was previously detected as a larval stage in fishes from Madeiran waters. In addition, our molecular studies demonstrate that Anisakis sp. A and the taxon Anisakis sp., previously found in other Mesoplodon spp., are the same species. The adults of Anisakis sp. A are morphologically similar to A. ziphidarum but with a shorter body length and longer spicules (right spicule 2.42 mm, left spicule 2.30 mm). Since the poor condition of the male tail cuticle prevented a proper description of the caudal plates and the pattern of caudal papillae, we propose to retain the name Anisakis sp. A until new males are described correctly.

Occurrence and identification of Anisakis spp. (Nematoda: Anisakidae) isolated from chum salmon (Oncorhynchus keta) in Korea

“…The ratio between esophagus and ventriculus length can be a distinguishing morphological character for differentiating A. simplex (s.s.) from A. pegreffi (Quiazon et al 2008), and our measurement data also overlapped with A. simplex (s.s.) in their studies. Morphological analyses have been used for anisakid nematode identification (Berland 1961;Grabda 1991;Iglesias et al 2008). However, identifications solely based on morphological differences lead to much controversy due to the limitation of taxonomically valuable characters (Mattiucci and Nascetti 2008).…”

Molecular characterization and phylogeny of anisakid nematodes from cetaceans from southeastern Atlantic coasts of USA, Gulf of Mexico, and Caribbean Sea

“…Host specificity does not allow C. multipapillatum individuals to reach maturity in dolphins. The record of larval A. simplex (s.s.) in the Gervais' beaked whale may also be an accidental infection because ziphiids are known to be specific for A. ziphidarum and A. nascettii (Paggi et al 1998;Pontes et al 2005;Iglesias et al 2008). Fig.…”

Additional records of metazoan parasites from Caribbean marine mammals, including genetically identified anisakid nematodes

“…A by Pontes et al (2005). Iglesias et al (2008) detected the presence of some adult worms from Blainville's beaked whales stranded along the Atlantic coasts of Spain; however, the nominal designation of the species was not possible because of the lack of male specimens in their collection that were in suitable condition to be analyzed morphologically. Our Caribbean data further confirms that this taxon belonging to the genus Anisakis is a species genetically closely related to A. ziphidarum, one with host preference for beaked whales (Ziphiidae; Mattiucci and Nascetti 2008).…”

“…Gibson et al (1998) reported A. simplex from a Blainville's beaked whale stranded on the British coast. Recently, Iglesias et al (2008) demonstrated by using sequences analysis of the mtDNA cox2 that the taxon Anisakis sp. detected as preadults in beaked whales in Valentini et al (2006) corresponds to that documented in fish at larval stages from Madeira and reported as Anisakis sp.…”