Reinhardorhynchus pacificus Diez, Reygel & Artois 2021, sp. n.
Creators: name: Diez, Yander L.
name: Monnens, Marlies
name: Aguirre, Rosa Isabel
name: Yurduseven, Rana
name: Jouk, Philippe
name: Van Steenkiste, Niels W. L.
name: Leander, Brian S.
name: Schockaert, Ernest
name: Reygel, Patrick
name: Smeets, Karen
name: Artois, Tom
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Platyhelminthes
Rhabditophora
Rhabdocoela
Koinocystididae
Reinhardorhynchus
Reinhardorhynchus pacificus

description: Reinhardorhynchus pacificus Diez, Reygel & Artois sp. n.
(Fig. 12D–F, 13)
urn:lsid:zoobank.org:act: C5DDBEEF-C3CA-456D-9330-440CFA8B10E4
Material and distribution. Observations on live specimens, whole mounted afterwards. Two whole mounts collected in Playa Venao (08°53’06”N; 79°36’07”W) (Type Locality), Vera Cruz, Panama (December 2, 2011), one of which is designated holotype (USNM 1642506), the other one in the USNM (1642507), coarse-grained sand with fine silt, salinity 30 ‰.
Etymology. The two specimens were found at the Pacific coast of Panama.
Diagnosis. Species of Reinhardorhynchus gen. n. with a copulatory bulb encompassing a papillary cirrus, an ejaculatory cirrus, an accessory cirrus, and two hooks. Ejaculatory cirrus ±171 μm long, armed with scale-like spines along its entire length that are ±5 μm wide proximally and ±2 μm wide distally. Few larger triangular spines occur proximally (±10 μm long) and distally (±4 μm long). Accessory cirrus ±92 μm long, proximally armed with ±6-μm-long triangular spines and distally with 3-μm-long triangular spines and ±3-μm-wide and scale-like spines. Distal rims of these spines serrated, bearing ±1-μm-long spinules. Papillary cirrus ±62 μm long, proximally cov- ered by fine spines of ±2 μm long and distally with ±6-μm-long triangular spines. The hooks are ±83 μm long and ±81 μm long, respectively.
Description. The specimens are 1.7 mm long, colourless, with two eyes (Fig. 13A: e). The brain (Fig. 13A: br) is located caudally from the proboscis. The proboscis (Fig. 13A: pr) has the typical koinocystidid morphology (see Brunet 1972; Karling 1980) and shows a strong junction sphincter; it represents 10% of the body length in live specimens. The pharynx (Fig. 13A: ph) has a diameter of ±15% of the body length in live specimens, and is located at 30–40%. Caudally in the body some eosinophilic glands occur (Fig. 13A: cgl).
The two testes (Fig. 13A: t) are located rostrally from the pharynx. The seminal vesicles (Fig. 12D & 13A: sv) fuse proximally from the copulatory bulb, forming a short seminal duct. The copulatory bulb is 363–403 μm long (x̄ = 383 μm; n = 2). It encompasses the prostate vesicle (Fig. 13A: pv), the ejaculatory cirrus (terminology of Karling 1978), an accessory cirrus, a papillary cirrus (terminology of Karling 1978), and two distal hooks. The ejaculatory cirrus (Fig. 12D–E & 13A: ci, 13B) is 162–180 μm long (x̄ = 171 μm; n = 2) and armed with scalelike spines over its entire length. These spines are 5–6 μm wide (x̄ = 5 μm; n = 20) proximally and 2–3 μm wide (x̄ = 2 μm; n = 20) distally. Additionally, a number of larger triangular spines occur proximally, measuring 6–13 μm (x̄ = 10 μm; n = 10), and a group of small triangular spines is present distally, measuring 3–4 μm (x̄ = 4 μm; n = 13). The accessory cirrus (Fig. 12D–E & 13A: ac, 13C) is 89–95 μm long (x̄ = 92 μm; n = 2), proximally armed with triangular spines 4–10 μm long (x̄ = 6 μm; n = 24) and distally with triangular spines 2–4 μm long (x̄ = 3 μm; n = 9) and scale-like spines 2–5 μm wide (x̄ = 3 μm; n = 15). The distal rim of the scale-like spines of the accessory cirrus is serrated, with 1-μm-long spinules. The spiny part of the papillary cirrus (Fig. 12D–E, 13A & 13D: pc) is 55–69 μm long (x̄ = 62 μm; n = 2) and proximally enclosed in a papilla (Fig. 13D: pa). Papilla and cirrus are separated from each other by a sphincter (Fig. 13D: sph). The papillary cirrus is proximally armed with fine spines, ±2 μm long, and distally with triangular spines, 4–8 μm long (x̄ = 6 μm; n = 6). The two funnel-shaped distal hooks are nearly equal in size. One hook (Fig. 12D–E & 13A: h 1, 13E) is 79–86 μm long (x̄ = 83 μm; n = 2) and 40–43 μm wide at its base (x̄ = 42 μm; n = 2). The other hook (Fig. 12D–E & 13A: h2, 13F) is 79–83 μm long (x̄ = 81 μm; n = 2) and 59–65 μm wide at its base (x̄ = 62 μm; n = 2).
Vitellaria were not observed. The oval-shaped ovaries (Fig. 13A: ov) are located rostrally from the copulatory bulb. The oocytes are organised in a row. The oviducts (Fig. 13A: od) open into the proximal end of the female duct. The female duct (Fig. 12D, 12F & 13A: fd) opens into the receptacle bursa (terminology of Karling 1981; followed by Reygel et al. 2011) (Fig. 13A: rb) through a sphincter (Fig. 13A: sph). The caudally-located bursa (Fig. 12D, 12F & 13A: b) opens into the female genital atrium via the bursal stalk. The uterus (Fig. 13A: ut) has a sphincter more or less at its midpoint. The common gonopore (Fig. 13A: cg) opens at 90%.
description: Published as part of Diez, Yander L., Monnens, Marlies, Aguirre, Rosa Isabel, Yurduseven, Rana, Jouk, Philippe, Van Steenkiste, Niels W. L., Leander, Brian S., Schockaert, Ernest, Reygel, Patrick, Smeets, Karen & Artois, Tom, 2021, Taxonomy and phylogeny of Koinocystididae (Platyhelminthes, Kalyptorhynchia) with the description of three new genera and twelve new species, pp. 451-500 in Zootaxa 4948 (4) on pages 476-478, DOI: 10.11646/zootaxa.4948.4.1, http://zenodo.org/record/4629235