A new species of Tantulocarida (Crustacea) parasitic on a deep-water cumacean host from the southwestern Atlantic, with a review of tantulocaridan host utilization, distribution, and diversity

Abstract

Abstract Tantulocaridans (Class Tantulocarida) are primarily known to parasitize copepods, tanaidaceans, and isopods while only single species have been recorded from amphipod, ostracod, and cumacean hosts. Examination of a collection of deep-water peracarids from the Campos Basin off northeastern Brazil resulted in the discovery of a tantulus larva attached to a juvenile Styloptocuma angustatum (Jones, 1984) (Cumacea, Nannastacidae), representing a new species and only the fifth record for this host group. The new species is provisionally assigned to the genus AphotocentorHuys, 1991 (Cumoniscidae) based on the proximally dilated terminal caudal ramus setae, the conspicuous polygonal surface ornamentation on the thoracic somites, the spinous processes around the posterior border of the abdomen, the dorsal abdominal surface pattern consisting of four continuous transverse lamellae, and the spinular ornamentation on the protopods of legs 2–6. The tantulus of A. kolbasovisp. nov. is characterized by its large body size (175 μm), disproportionally long cephalic shield, the presence of paired papillae on the midventral surface of the cephalon, and the unique swimming leg setal formula, displaying the highest number of setation elements ever reported for leg 1. Except for the asymmetrically arranged median pores, the new species exhibits the full complement of cephalic pores, including the anterior pore AV. Current classification, known stages, tantulus body length, and distribution of all valid tantulocaridan species are presented. Literature records of Tantulocarida, including host group/species and depth, as well as those based exclusively on tantulus stages from the temporary meiobenthos or unidentified stages from the meroplankton are summarized. The authenticity of recently reported tantulus larvae on the lysianassid amphipod Lepidepecreella debroyeriSchiaparelli, Alvaro, Kilgallen, Scinto & Lörz, 2015 from Terra Nova Bay (Ross Sea, Antarctica) is scrutinized. Tumour-like anomalies on the exoskeleton of planktonic copepods in the central Red Sea and around hydrothermal vent fluids off Taiwan have erroneously been attributed to tantulocaridan infections.