Haplopharynx papii, Schockaert, Ernest R., 2014

Schockaert, Ernest R., 2014, Marine Macrostomorpha (Platyhelminthes, Rhabditophora) from the Algarve (Southern Portugal), Zootaxa 3872 (5), pp. 577-590 : 586-588

Haplopharynx papii n. sp.

Localities in the Algarve. Faro ( Portugal), (1) Type locality: Ria Formosa, 36° 59.961 N, 7° 54.964 W. Lower intertidal, fine sand with silt. Two adults found on 7 October 2013. Three juvenile individuals of Haplopharynx spec. were found in the Ria Formosa at 37° 0.317 N, 7° 58.080 W, between the roots of Spartina sp. in relatively coarse and clean sand (19 September 2012, 25 September 2012 and 18 October 2013). (2) Beach exposed to the ocean on the Anção peninsula, about mid-way between Praia de Faro and the bridge of Quita do Lago. Mid-littoral zone at 50–60 cm deep in damp relatively coarse and clean sand (at 37° 01.669 N, 8° 01.092 W on 8 September 2011).

Other location. Near Zanca Sant’Andrea, North of the Island of Elba ( Italy), collected by Lukas Schärer at 13 m depth on sand flat at the bottom of a rock ledge (42°8087 N, 10°1418 E; 3 May 2010).

Material. Two whole mounts from the Ria Formosa, one of them designated holotype ( SMNH Type-8581 and HU nr. PT 564) and one from the exposed beach (HU nr. VI.3.24). Micrographs and videos of two individuals from Elba (specimen accession codes MTP LS 720 and MTP LS 724). The diagnosis and the description below are based on the individuals from Faro, unless stated otherwise.

Diagnosis. Species of Haplopharynx with a straight stylet of 50–55 mm length and an oblique terminal opening and six needles 42–43 mm long, four almost parallel with the stylet; two oblique and closer to the stylet, all with a small wing at one side and a larger wing at the other side.

Derivation of the name. In honour of, and in gratitude to Prof. Floriano Papi (Emeritus of the University of Pisa, Italy), who introduced me to the study of the “Turbellaria”.

The animals are about 2.5 mm long (one measured in a whole mount), with the copulatory organ about in the middle of the animal. The proboscis most resembles that of H. quadristimulus ( Ax, 1971) with eight gland tracks. In the hard parts of the copulatory organ, the stylet is straight, 50 and 52 mm long and 11 and 14 mm in diameter, with an oblique terminal opening. Next to the stylet, there is a ring of four needles about parallel to the stylet. These four needles have a narrow lateral transparent keel or wing at one side and a larger wing at the opposite side. There are two more needles making an angle with the stylet. These have a small keel at the side directed to each other and a very large keel at the other side. All six needles are of almost the same length, 42 mm in one individual and 43 mm in the other one. In the individuals from Elba, the stylet is 72 and 75 mm and the needles, with 55 and 58 mm, are longer than in the individuals from Faro.

A a Αf D

Βf ⊂f Ε Until now, only two species of Haplopharynx have been described, H. rostratus Meixner, 1938 , known from N. European coasts from Bergen in Norway ( Karling 1965) to the Scilly Islands in Cornwall, England ( Faubel & Warwick 2005) and H. quadristimulus Ax, 1971 , from the western French Mediterranean coast (Canet Plage, Languedoc Roussillon, France). H. rostratus has a slightly curved stylet 80–89 µm long, with an oblique terminal opening and a ring of 7–9 needles of 60–69 µm length, without a keel, and no proximal spatulated end ( Karling 1965 and Pawlak 1969). H. quadristimulus has a straight stylet 80–82 µm long with a funnel-like proximal end, accompanied by four needles of 65–67 µm length, with a clear keel and obviously spatulated at the proximal end. In the copulatory organ of the Faro individuals, the stylet is not curved nor does it have the funnel-like proximal end. The three individuals have six needles accompanying the stylet in a characteristic pattern and with a characteristic aspect. The stylet and the needles are shorter than in the known species. These differences are sufficiently obvious to consider the Faro population a new species. The individuals from Elba undoubtedly belong to the same species.

Rieger (1977) claimed to have found H. rostratus in the Mediterranean (Adriatic and Tyrrhenian Seas), and also on the N. American east coast and in Bermuda, stating that, “though more careful study is necessary, the material so far suggests only extremely small differences between populations on the two sides of the Atlantic”. On the other hand, he also found H. quadristimulus on intertidal beaches of N. Carolina, adding that “there appear to be slight but significant differences between the N. Carolina and the French form”. The micrographs in his Fig. 7 do indeed suggest that species other than H. quadristimulus are involved. Material of this species, called the “Carolina form”, was used by Doe (1986a; 1986b) for a TEM analysis of the copulatory organ. Laumer & Giribet (2014) used the DNA of an unnamed species of Haplopharynx form Bocas del Toro (Eastern Panama) in their search for the origin of ectolecithality in Platyhelminthes.