Dive into the sea: first molecular phylogenetic evidence of host expansion from terrestrial/freshwater to marine organisms in Mermithidae (Nematoda: Mermithida)

Abstract

We report the first mermithid nematode found to be parasitic in a marine tanaidacean crustacean. Ten host tanaidaceans were collected from a depth of 52 m in Otsuchi Bay, Iwate, Japan, north-western Pacific, and identified as a species in the tanaidid genus Zeuxo Templeton, 1840. Nematodes occurred in the host's body cavity; in one case, at least two individuals inhabited a single host. We provide a brief description and illustrations of the morphology of the nematode. In a phylogenetic reconstruction based on the 18S ribosomal RNA gene, the nematode nested in a clade otherwise containing mermithids from terrestrial or freshwater hosts, showing an expansion in host utilization in Mermithidae Braun, 1883 from terrestrial/freshwater hosts to a marine organism.

Parasites of firebugs in Austria with focus on the “micro”-diversity of the cosmopolitan trypanosomatid Leptomonas pyrrhocoris

“…The two isolates from firebugs are shown in crimson color. The tree was rooted according to the topology of a previously inferred tree (Kakui and Shimada 2022 ). The numbers at branches are ultrafast bootstrap supports.…”

A new nematode (Mermithidae) and spider (Araneae) associations, along with a molecular analysis of mermithids hosted in the spider

“…bumblebees [ 1 ], hornets [ 2 ], hemipterans [ 3 ], moths [ 4 ] and beetles [ 5 ]. However, they parasitize other arthropods, such as spiders [ 6 ] and crustaceans [ 7 ], and they can parasitize other invertebrates, e.g. slugs [ 8 ].…”

“…Therefore, we know extremely little about the taxonomy or phylogeny of mermithids parasitizing in spiders, especially considering the fact that these parasitoids are often and widely recorded. Up to now, only ve sequences of 18S rRNA, from mermithids emerged from two spider species, have been published [ 17,18 ], and only sequences of mermithids from Tetragnatha have been included in papers revealing a phylogenetic analysis of Mermithidae [ 1,7,17,19 ].…”

Diversity under a magnifier lens: the case of Typhlotanaidae (Crustacea: Tanaidacea) in the N Atlantic

“…The last is composed of complex structures such as prickly tubercles, microtrichia or serrated spines, and is assumed to help motility of the animal inside the self-constructed housing-tube. Typhlotanaids are believed to be unselective detritivores 29 and also hosts for tantulocarids 30 and endoparasitic nematodes 31 . As with other tanaids, they have limited dispersal abilities because of their brooding behaviour and demersal juvenile stages 32 , 33 and so are considered an ideal model for zoogeographic studies and assessments of the effects of anthropogenic impact in deep-sea ecosystems 32 , 34 .…”