Carcharodorhynchus spiniferus, Diez & Reygel & Artois, 2019

Diez, Yander L., Reygel, Patrick & Artois, Tom, 2019, Schizorhynchia (Platyhelminthes, Rhabdocoela) from eastern Cuba, with the description of fifteen new species, Zootaxa 4646 (1), pp. 1-30 : 16-18

Carcharodorhynchus spiniferus sp. n.

( Fig. 10 )

http://zoobank.org/ urn:lsid:zoobank.org:act:D32E2CF9-4285-4535-B79C-8C1DD6ACA8EB

Material. Observations on live animals, whole mounted afterwards. Three whole mounts from Siboney (type local- ity) (February 7 & May 15, 2016; April 4, 2017), one of which is designated holotype ( FMNH https://id.luomus. fi/KV.615), the others in HU (X.1.11– X.1.12), one specimen collected in fine-grained sand, 0.2 m depth; the second one in the intertidal, upper 20 cm of coarse-grained sand; and the third one on Ulva lactuca , 0.3 m depth, salinity 34–35 ‰. One whole mount from Macabí (April 23, 2017) (HU X.1.13), intertidal, upper 10 cm of fine-grained sand, salinity 34 ‰.

Etymology. The epithet refers to the fact that the cirrus is armed with long spines.

Diagnosis. Species of Carcharodorhynchus with proboscis asymmetric; largest lip 87 µm long and the smallest 70 µm. Inner side of both lips covered with small denticles. Largest lip with about 4–6 rows of denticles, smallest one with 2–3 rows of denticles. Belts of denticles continuous between both lips. The denticles on the largest lip are about 0.3 µm long in the proximal third, and 0.6 µm in the middle and distal thirds. On the smallest lip the ±0.6-µmlong denticles are located in the proximal and the middle third. Cirrus 50 µm long, armed with long spines, 23 µm long in the proximal two-thirds of its length and 5 µm long in the distal third. The largest spines bear a proximal small tooth in their middle.

Description. Living animals slender, 1–1.5 mm long, 0.6–1.5 mm long in the whole mounts (x = 1 mm; n = 4), yellow, without eyes. Epidermis opaque, thick and hampering the study of the internal morphology on live animals. Proboscis ( Fig. 10A : pr, 10B–C) with asymmetric lips; largest lip 82–90 µm long (x = 87 µm; n = 3) and the smallest 68–73 µm long (x = 70 µm; n = 3). The inner side of the largest lip is covered by 4–6 rows of denticles from its most basal part towards the distal tip, leaving only the distal 20% without denticles. These denticles are ± 0.3 µm long in the basal third and ± 0.6 µm long over the distal two-thirds. The inner side of the smallest lip is covered by 2–3 rows of denticles from its most basal part towards its middle third, leaving the distal ±30% without denticles; these denticles are equal in size, ± 0.6 µm long. The belts of denticles are continuous between the lips. In live animals, spherical to oval-shaped glands ( Fig. 10B : prg) were observed on the inner surface of the lips. Pharynx ( Fig. 10A & 10D : ph) located at 70%, 94–129 µm in diameter (x = 107 µm; n = 3).

Testes were observed only in one specimen (Macabí). There is one pair, which is located rostrally from the pharynx. Two large seminal vesicles ( Fig. 10D : sv) open separately into the copulatory bulb. Copulatory bulb ( Fig. 10A : cb, 10D–F) situated just caudally from the pharynx, 80–94 µm long, comprising the prostate vesicle ( Fig. 10D : pv) and the armed cirrus. Cirrus ( Fig. 10D : ci, 10E–F) 48–53 µm long (x = 50 µm; n = 4), armed with 21–25-µm-long spines in its proximal two-thirds (x = 23 µm; n = 6), 3–6-µm-long in its distal third (x = 5 µm; n = 8). The largest spines show a small tooth more or less in their middle ( Fig. 10 E–F: to).

The paired vitellaria extend at both sides of the body from just behind the brain to the distal body third. Globular bursa located caudally from the copulatory bulb. Ovaries not observed.

Figures

FIGURE 10. Carcharodorhynchus spiniferus sp. n.. A, body. B–C, proboscis. D, copulatory bulb. E–F, cirrus. A–B, from a live animal. C–F, from whole mounts. C & F, from a reference specimen (HU X.1.11 & X.1.13, respectively). D–E, from the holotype.