Gastropoda: Opisthobranchia: Philinidae)

ZOOSYSTEMATICA ROSSICA, 18(2): 205–211 25 DECEMBER 2009

Description of a new genus Praephiline gen. nov. (Gastropoda: Opisthobranchia: Philinidae)

E.M. CHABAN & E.V. SOLDATENKO

E.M. Chaban, Zoological Institute, Russian Academy of Sciences, Universitetskaya Emb. 1, St. Petersburg 199034, Russia. E-mail: [email protected] E.V. Soldatenko, Zoological Institute, Russian Academy of Sciences, Universitetskaya Emb. 1, St. Petersburg 199034, Russia. E-mail: [email protected]

A new genus of opisthobranch mollusks Praephiline gen. nov. is described for Philine finmarchica M. Sars, 1858. Philine finmarchica differs significantly from the type of Philine – Philine aperta in the morphology of gizzard and male copulatory apparatus. The status of Philine thurmanni thurmanni Marcus & Marcus, 1969 and Philine thurmanni chilla Marcus & Marcus, 1969 is discussed; they are considered to be distinct species and assigned to the new genus – Prae- philine thurmanni (Marcus & Marcus, 1969) and Praephiline chilla (Marcus & Marcus, 1969). Key words: taxonomy, gastropod mollusks, Gastropoda, Philinidae, Philine, Praephiline, new genus

INTRODUCTION Philine finmarchica M. Sars, 1858 belong to different genera, primarily because of the Family Philinidae has the greatest di- differences in the morphology of the gizzard versity of forms among cephalaspidean mol- and the copulatory apparatus. We describe lusks, so it is not surprising that several gen- a new genus Praephiline for Philine finmar- era were described in this family. But “the chica and give an annotated diagnosis for genera Hermania Monterosato, 1884, Laona Philine. A. Adams, 1865, Philinorbis Habe, 1950, Yokoyamaia Habe, 1950 and Globophiline RESULTS Habe, 1958 erected on differences of shell form and, in the case of Laona, on the loss Philine Ascanius, 1772 of the gizzard, are considered to be unneces- sary” (Rudman, 1972: 186). This view was Type species: Philine quadripartita Asca- supported by Gosliner (1980: 347). Based nius, 1772 (= Bulla aperta Linnaeus, 1767). on this, Valdés (2008) provided a list of syn- Diagnosis. Shell flattened dorso-ven- onyms of Philine Ascanius, 1772 including trally, almost circular in outline. Radula almost all the described genera except Spin- 1:0:1. Gizzard plates strongly calcified with iphiline Gosliner, 1988. The latter genus has two holes on outer surface; paired gizzard apomorphies in the shell form, morphology plates larger, of the same size, triangular of the gizzard plates, and length of the vis- with extended front and rear ends; unpaired ceral loop (Gosliner, 1988: 89). We agree plates narrower. Plates bound by continu- that division of philinids based on differ- ous sheath consisting alternately of muscle ences of the shell form is artificial. However, and thin horny layer. Copulatory apparatus accumulated data on the morphology of the includes a bag with a hammer shaped pe- Atlantic philinid species (Brown, 1933–34; nis, incurrent and ejaculatory ducts, com- Pruvot-Fol, 1930; Marcus & Marcus, 1968; ing out of the penial sheath; together they Bouchet, 1975, Marcus, 1973; Chaban & form an extension – seminal vesicle. Long Soldatenko, 2009) clearly indicate that at prostate with smooth walls begins from least Philine aperta (Linnaeus, 1767) and seminal vesicle. Tip of prostate connected

© 2009 Zoological Institute, Russian Academy of Scienсes 206 E.M. CHABAN & E.V. SOLDATENKO. PRAEPHILINE – NEW GENUS OF GASTROPOD MOLLUSKS with penis sheaths by a connective band. semi-lunar in cross section. Penial papilla Incurrent duct with thin dense shiny walls. hammer-shaped, with spoon-shaped muscle Long transparent ejaculatory duct divided mass around the papilla base; hole of ejacula- lengthwise by a partition into 2 equal chan- tory duct not closed with muscular folds. nels and ends in the distal appendages of penis, its hole closed with muscular folds. Praephiline finmarchica (M. Sars, 1858), new combination Philine aperta (Linnaeus, 1767) (Figs 1d–f, 2b, e) (Figs 1a–c, 2a, c, d) Philine finmarchica M. Sars, 1858: 49. Bulla aperta Linnaeus, 1767: 1183. Philine finmarchica: G.O. Sars, 1878: Tab. 18, Philine aperta: Vayssiére, 1880: Pl. 8, Figs 70–72, Figs 10a–c, 11 (shell), Tab. XII, Figs 1, 2, Pl. 9, Figs 73–82, Pl. 10, Figs 83, 84; Guiart, 3 (radula); Lemche, 1948: 96 (synonymy); 1901: 29 (synonymy), 33–42 (biology), Figs Marcus & Marcus, 1969: 10, 12, Figs 13–16 40–42 (gizzard plates), 105–111, Figs 58–62 (gizzard and penial morphology); Ivanov et (central nervous system), 146–148, Figs 86, al., 1985: Fig. 131 (gizzard); Gosliner, 1994: 88 (reproductive system), 159–178 (devel- Fig. 58a (central nervous system, scheme); opment); Pruvot-Fol, 1930: 45–49, Figs 4–5 Golikov, 1994: 60, Fig. 117 (distribution), (morphology); Brown, 1934: 179–210, Figs Fig. 139f (shell); Chaban & Soldatenko, 1–38 (morphology, development); Lemche, 2009: 6, 8, Figs 1c–g, 3a–f, 4c, d (shell, penial 1948: 90–91 (synonymy); Thompson, 1976: morphology). 132, Figs 68–69; Chaban & Soldatenko, Diagnosis. Shell, gizzard plates and wall, 2009: 6, Figs 1a, b, 2a–f, 4a, b (shell, penial and ejaculatory duct the same as in diagno- morphology). sis of the genus. Radula 1:0:1. Penial papilla Diagnosis. Corresponds to that of the hammer-shaped, its distal appendage bear- genus. Distal end of penial papilla appears ing transverse ridges and warts; penis with smooth with optic microscope, but is actual- spoon-shaped muscle mass around the base ly covered with small warts and short longi- of papilla. Ejaculatory duct ends at the base tudinal folds (Chaban & Soldatenko, 2009). of penial papilla; the hole not closed with muscular folds. Prostate long, with shallow Praephiline gen. nov. pocket protrusions in the middle part. Notes. Philine thurmanni thurmanni Type species: Philine finmarchica M. Sars, Marcus & Marcus, 1969 is close to P. fin- 1858. marchica. It was originally described from Diagnosis. Shell well developed, pear specimens collected in the South Atlantic shaped, from 2.5 whorls, apex flattened. Ocean off the Argentina coast. The two spe- Shell sculpture consists of thin dense spi- cies are similar in the morphology of shell, ral grooves. Radula (1): 1:0:1: (1). Gizzard gizzard wall and gizzard plates, and both plates strongly calcified, identical in size and have a muscular spoon-shaped flap. Philine shape, large, rod-shaped, slightly flattened thurmanni thurmanni resembles P. finmar- with truncated tips, with outer crest, about chica in having the orifice not closed with three times as long as wide. Annular muscu- muscular folds but differs from the latter in lature of gizzard consists of an outer entire the presence of marginal teeth, the absence layer, surrounding the gizzard, and an inter- of crests on penial papilla, and the ejacula- rupted inner one, connecting the crests of tory duct ending in the distal appendages of the plates. Gizzard wall covered with a solid penis. We consider Philine thurmanni thur- ring of connective tissue. Ejaculatory duct manni as a distinct valid species assigned to short, with strongly developed muscular the new genus Praephiline thurmanni. wall; it has 2 unequal channels: the central Another former subspecies, Philine thur- one narrow, circular, and the peripheral one manni chilla Marcus & Marcus, 1969 from

Fig. 1. Philine aperta: gizzard (a); gizzard plates, inner view (b); gizzard plates: paired plates, outer view, unpaired plate, lateral view (c); Praephiline finmarchica: gizzard (d); gizzard plates, inner view (e); gizzard plates, two plates in outer view, one plate, lateral view (f). Scale bar (a–d, f): 3 mm.

Fig. 2. Philine aperta, cross section of gizzard, scheme after Brown (1934) (a); Praephiline finmarchica, cross section of gizzard, scheme after Marcus & Marcus (1969) (b); part of copulatory apparatus of Philine aperta, after Pruvot-Fol (1930) (c); cross section of ejaculatory duct, scheme: Philine aperta, based on Pruvot-Fol (1930) (d), Praephiline finmarchica, based on Chaban & Soldatenko (2009) (e). Abbreviations: ej, ejaculatory duct; hl, horny layer connecting muscle sheets; m, gizzard muscle sheet; pl, gizzard plate; pr, prostate; s, stomodeal lining.

© 2009 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 18(2): 205–211 E.M. CHABAN & E.V. SOLDATENKO. PRAEPHILINE – NEW GENUS OF GASTROPOD MOLLUSKS 209 the South Pacific Ocean off the middle of the central nervous system: the supraintesti- Chile differs from Praephiline thurmanni in nal and pleural ganglia of Praephiline finmar- the absence of marginal teeth and a differ- chica are connected with a short connective ent form of muscular bulge around the base (see Gosliner, 1994: Fig. 58a), while those of the penial papilla (see Marcus & Marcus, of Philine aperta lie very close together (see 1969: 18, Fig. 29). We consider it as a valid Vayssiére, 1880: Pl. 9, Fig. 81; Guiart, 1901: species assigned to the new genus, Praephi- Fig. 59; Brown, 1934: Fig. 23). line chilla. Praephiline gen. nov. differs from the type species of both known valid genera DISCUSSION close to it and the genera regarded as syn- onyms of Philine. Spiniphiline as described It follows from the works by Brown by Gosliner (1988) has apomorphies in the (1934), Marcus and Marcus (1969), and form of shell and gizzard plates (which are Pruvot-Fol (1930) that Praephiline finmar- unpaired, rudimentary, and round) and the chica and related species differ significantly male copulatory system (the prostate is from Philine aperta in a number of morpho- simple and the penis is finger-shaped) (Gos- logical characters: 1) shell form; 2) mor- liner, 1988). phology of gizzard plates; 3) morphology of Philine scutulum Loven, 1846, the type of the gizzard wall (table). We also found sig- Ossiania Monterosato, 1887, is a synonym nificant differences in their apparently very of Philine quadrata. Due to reduction of the similar copulatory apparata, namely 4) in the gizzard plates, the body of this species can morphology of the ejaculatory duct and 5) in be drawn into the shell, contrary to what is the morphology of the penis (Chaban & Sol- observed in the new genus. There are signif- datenko, 2009). There are also differences 6) icant differences in morphology of the male in the degree of concentration of ganglia in copulatory apparatus: Philine quadrata has

Table. Comparison of characters of the type species of Philine and Praephiline gen. nov.

Spe- Morphology of ejacu- End of ejacula- Gizzard plates Gizzard wall Penis cies latory duct tory duct

divided by a longitu- is in the distal hammer-shaped almost triangular dinal partition into 3 separate muscle appendage of penis without paired plates with two 2 equal semicircular strips connected penis (2), its crests, without holes on outer surface; parts (2), its walls by a horny layer hole is closed a muscle mass the unpaired plate is are composed of a (1) with muscular around the base of

Philine aperta partially reduced (1) single-layered ciliated folds (4) penial papilla (1) epithelium (1)

consists of two channels with thick at the base of hammer-shaped thick sheath of muscular walls and penial papilla, penis with crests circular muscles ciliated epithelium in- uniform rod-shaped the hole is not and warts, with covered with a side, the inner channel (3) closed with a muscle mass solid ring of con- is narrow, cylindrical, muscular folds around the base of nective tissue (3) the external one is (4) penial papilla (4) semi-lunar in cross

Praephiline finmarchica section (4)

Data from: 1 – Brown (1934); 2 – Pruvot-Fol (1930); 3 – Marcus & Marcus (1969); 4 – Chaban & Soldatenko, 2009.

© 2009 Zoological Institute, Russian Academy of Scienсes, Zoosystematica Rossica 18(2): 205–211 210 E.M. CHABAN & E.V. SOLDATENKO. PRAEPHILINE – NEW GENUS OF GASTROPOD MOLLUSKS a short prostate and a penial sac with a digi- ACKNOWLEDGMENTS tiform penial papilla (Rudman, 1972, Cha- ban, 1999). We are thankful to Olga Chaban (St. Peters- Philine scabra (Muller, 1776), the type burg) for her help with computer and English correction. species of Hermania Monterosato, 1884, has an elongate shell, rather cylindrical in outline in apertural view, with a very un- REFERENCES usual form of sculpture (Thompson, 1976) and a different male copulatory system, Bouchet, Ph. 1975. Opisthobranches de profon- deur de l’Océan Atlantique. 1. Cephalaspi- with a complex penis but a simple prostate dea. Cahiers de biologie marine, 16: 317–365. (Bouchet, 1975). Brown, H.H. 1933–1934. A study of a tecti- Yokoyamaia ornatissima (Yokoyama, branch gastropod mollusk, Philine aperta 1927), the type species of the genus Yokoya- (L.). Transactions of the Royal Society of Ed- maia Habe, 1950, has a similar gizzard plate inburgh, 17(1): 179–210. but a strongly reduced shell that only in- Chaban, E.M. 1999. Rakovinnye zadnezhabernye completely covers the visceral sac; the mor- mollyuski otryadov Cephalaspidea i Anaspi- dea severnykh i dal’nevostochnykh morey phology of the male copulatory apparatus is Rossii [Shelled opisthobranchiate mollusks closer to that of the genus Philine (Chaban, of the orders Cephalaspidea and Anaspidea 1999). of northern and Far-East seas of Russia]. Dis- Philine pygmaea Yokoyama, 1922, the sertation Cand. Sci. (Biol.), St.-Petersburg, type species of Choshiphiline Habe, 1958, ZIN RAN. 256 p. (In Russian). is considered a synonym of Philine japonica Chaban, E.M. & Soldatenko, E.V. 2009. Com- Lischke, 1872 (Valdes, 2008). The latter is a parative morphology of the hammer-shaped penises of two species of opisthobranch mol- typical representative of the genus Philine. lusks of the genus Philine Ascanius, 1772 Globophiline kawamurai Habe, 1958, the (Opisthobranchia: Cephalaspidea: Philini- type species of Globophiline Habe, 1958, dae). Zoosystematica Rossica, 18(1): 5–10. has a different copulatory system: compact, Golikov, A.N. 1994. Shell-bearing gastropods of with a very short prostate and a finger- the Arctic. Tropa, Moscow. 185 p. shaped penis (Chaban, 1999). Gosliner, T.M. 1980. Systematics and phylog- Pseudophiline hayashii Habe, 1976, the eny of the Aglajidae (Opisthobranchia: Mol- lusca). Zoological Journal of the Linnean So- type of Pseudophiline Habe, 1976, has no ciety, 68: 325–360. plates and a strongly reduced radula (Ki- Gosliner, T.M. 1988. The Philinacea (Mollusca: tao et Habe, 1982). The morphology of Gastropoda: Opisthobranchia) of Aldabra Philinorbis teramachii Habe, 1950, the type Atoll, with descriptions of five new species species of the genus Philinorbis Habe, 1950, and a new genus. Biological Society of Wash- is unknown, but its shell is very similar to ington, Bulletin, 8: 79–100. that of Pseudophiline hayashii, as noted by Gosliner, T.M. 1994. Gastropoda: Opisthobran- chia. In: Harrison, F.W. & Kohn A.J. (Eds) Habe (1976: 154). Microscopic anatomy of invertebrates. 5. Mol- Philine monterozati Jeffreys in Montero- lusca, 1: 253–355. Wiley-Liss Inc., New York. zato, 1874, the type of the genus Philingw- Guiart, J. 1901. Contribution a l’étude des Gas- ynia Nordsieck, 1972, is closer to the genus téropodes Opisthobranches et en particulier Philine in the morphology of the copulatory des Céphalaspides. Mémoires de la Société apparatus and gizzard (Bouchet, 1975). Zoologique de France, 14: 1–217. Retusophiline Nordsieck, 1972 with the Habe, T. 1976. Eight new and little known ce- phalaspid Opisthobranchia from Japan. Ve- type species Bulla lima Brown, 1827, has nus, The Japanese Journal of Malacology, outgrowths on the posterior edge of the 35(4): 151–157. head shield and no gizzard plates (Nord- Ivanov, A.V., Polyanski, Yu.I. & Strelkov, A.A. sieck, 1972). 1985. Bol’shoy praktikum po zoologii bespoz-

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