Ammotrypanella sp. (NHM_2114)

Wiklund, Helena, Neal, Lenka, Glover, Adrian G., Drennan, Regan, Muriel Rabone, & Dahlgren, Thomas G., 2019, Abyssal fauna of polymetallic nodule exploration areas, eastern Clarion-Clipperton Zone, central Pacific Ocean: Annelida: Capitellidae, Opheliidae, Scalibregmatidae, and Travisiidae, ZooKeys 883, pp. 1-82 : 1

Ammotrypanella sp. (NHM_2114) Fig. 10 A–E

Material examined.

NHM_2114 NHMUK ANEA 2019.7113, coll. 20 Mar. 2015, 19°27.874N, 120°01.525W, 4026 m, http://data.nhm.ac.uk/object/f4492dd1-8088-47c6-97d9-32e43ae99552.

Description.

Single, minute, damaged specimen; now with posterior part of the body removed for molecular analysis. Anterior fragment 1.6 mm long 0.2 mm wide for about 16 chaetigers (chaetae observed on only 11 of these, the rest of the fragment damaged with chaetae missing). Ventral groove along the entire length of the fragment. First six chaetigers crowded. Preserved specimens pale yellow in ethanol; live specimen translucent with orange gut ( Fig. 10A ). Prostomium broad (slightly longer than wide) and anteriorly bluntly rounded, bearing distinct bi-articulated palpode, with globular distal articulation ( Fig. 10 B–D ). Parapodia distinct, biramous; as a small lobe in chaetigers 1-9, becoming indistinct in the rest of the fragment. All chaetae observed simple capillaries ( Fig. 10E ).

Additional morphological observations from live specimen.

Upon collection the live specimen was imaged and appears to be complete. Presence and distribution of branchiae cannot be established from the image. The anal tube was probably missing upon collection of the specimen.

Genetic data.

GenBank MN217414 for 16S and MN217494 for 18S. COI was unsuccessful for this specimen, no identical GenBank matches for 16S or 18S. Ammotrypanella sp. (NHM_2114) cluster with the Ammotrypanella keenani sp. nov., Ammotrypanella sp. (NHM_1653) and Ammotrypanella kersteni sp. nov. in our phylogenetic analyses ( Fig. 23 ).

Remarks.

Although important diagnostic features cannot be fully confirmed in this specimen, in the phylogenetic tree it falls into a well-supported clade containing Ammotrypanella species and likely represents another species in this genus reported from UKSR material. At present, morphological information obtained from this single representative is limited which prevent us from providing a formal description.

Figures

Figure 10. Ammotrypanella sp. NHM _ 2114 (specimen NHM _ 2114). A Live images, whole specimen with detail of anterior B Lab images, fragmented whole specimen, post-staining, (faded stain, anterior fragment [left], posterior fragment [right],) C Lab image, anterior fragment, post-staining, faded stain D Lab image, detail of anterior and palpode E Lab image, detail of capillary chaetae. Scale bars: 1 mm (B); 250 μm (C) 50 μm (D); 25 μm (E).

Figure 23. Phylogenetic analysis of Opheliidae. 50 % majority rule tree from the Bayesian analyses using 18 S and 16 S, with posterior probability values on nodes. Twenty-nine taxa from GenBank were included, and Capitellidae and Echiura was chosen as outgroup following the annelid phylogeny of Weigert and Bleidorn (2016).