Two new cryptogonimid genera (Digenea, Cryptogonimidae) from Lutjanus bohar (Perciformes, Lutjanidae): analyses of ribosomal DNA reveals wide geographic distribution and presence of cryptic species

Abstract

We describe three new species of Cryptogonimidae belonging to two new genera, Caulanus gen. nov. and Latuterus gen. nov., from the large piscivorous reef fish Lutjanus bohar ForsskDl, 1775, recovered from Heron and Lizard Islands off the Great Barrier Reef and Rasdhoo Atoll, Maldives. To support our morphologically based taxonomic approach, three nuclear ribosomal DNA regions (28S, ITS1 and ITS2) were sequenced and analysed to explore the geographic distribution and integrity of the putative species recovered from these widespread localities. Sequencing of the rDNA regions included multiple replicates and revealed three distinct genotypes. Two of the observed genotypes were associated with phenotypically similar specimens of Latuterus, but were each restricted to a single locality, Lizard Island, GBR or Rasdhoo Atoll, Maldives. A posteriori analysis of the associated morphotypes revealed distinct morphological differences and these consistent differences, in combination with the consistent genetic differences led to the recognition of two distinct species in the system. Caulanus is distinguished by having oral spines, caeca which open via ani at the posterior end of the body, tandem testes and uterus that extends from the posterior end of the body to the pharynx. Latuterus is distinguished by lacking oral spines, having multiple/follicular testes, a uterus that is extensive in both fore-and hindbody and vitelline follicles which are confined to the region from the pharynx to oral sucker. Caulanus thomasi sp. nov. had identical sequences for all of the rDNA regions examined from specimens recovered from all three localities, indicating that this species has a wide Indo-Pacific distribution. The species reported here are evidently restricted to Lutjanus bohar because they were never found in large numbers of other lutjanid species sampled at the same localities.

Cryptic species of Euryakaina n. g. (Digenea: Cryptogonimidae) from sympatric lutjanids in the Indo-West Pacific

“…The interspecific variation observed here between species of Euryakaina is higher than that observed between species of Beluesca and many species within Retrovarium and Siphoderina (Table 4). Surprisingly, the amount of genetic variation over the rDNA regions examined here between species of Euryakaina is larger than the intergeneric variation observed between species of Caulanus and Latuterus by Miller & Cribb (2007c), which are morphologically clearly distinct from each other.…”

“…Latuterus maldivensis Cribb, 2007 andL. tkachi Miller &Cribb, 2007, both infect Lutjanus bohar, but at two widely separated localities (Lizard Island and the Maldives); although morphologically similar, they can be distinguished by body size and differ by only 3 bp in the LSU and 6 bp in the ITS regions (Miller & Cribb, 2007c). The interspecific variation observed here between species of Euryakaina is higher than that observed between species of Beluesca and many species within Retrovarium and Siphoderina (Table 4).…”

New genus of opecoelid trematode from Pristipomoides aquilonaris (Perciformes: Lutjanidae) and its phylogenetic affinity within the family Opecoelidae

“…recent studies on the opecoelids (Jousson et al 2000, Jousson andBartoli 2001) and other groups (see Poulin 2011) have revealed that morphologically similar species occurring in different hosts (curran et al 2013) or in different geographical locations (Miller andcribb 2007, Detwiler et al 2010) are sometimes cryptic species. our specimens identified as N. lanceolata are similar to those reported by both Price (1934) andreimer (1987), but future workers should use sequence data to compare specimens from the indian ocean with those of this study to see if N. lanceolata reported by reimer (1987) actually represents a cryptic species.…”

Are cryptic species a problem for parasitological biological tagging for stock identification of aquatic organisms?

“…Miller and Cribb (2007b) observed that two genotypes were associated with phenotypically similar specimens of Latuterus restricted to the GBR and the Maldives respectively. Miller and Cribb (2007b) observed that two genotypes were associated with phenotypically similar specimens of Latuterus restricted to the GBR and the Maldives respectively.…”