Notes on Some Opisthobranch Gastropods from the Chesapeake Bay^
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Notes on Some Opisthobranch Gastropods from the Chesapeake Bay^ EVELINE du BOIS-REYMOND MARCUS Universidade de Sao Paulo Faculdade de Filosofia, Ciencias. e l.etras Caixa Postal 6994 Sao Paulo. Brazil ABSTRACT: Seventeen species of opisthobranchs from Chesapeake Bay were studied, 4 Cephalaspidea, 6 Ascoglossa, 5 Doridoidea, and 2 Eolidoidea. The radula of " A n e o n ” puiicloslriatus from Chesapeake Bay shows that the species comes under Kiel axis Dali, 1871, hence the species called punclostriatus from Brazil, a true A clean, receives a new name, Acleon peU’cais. Two species of Haminoea. distinguished by a small cylindrical shell, //. succinea. and a larger ovoid shell, H. solilaria. have consistent anatomical features. The generic name of Stilii>er has to be replaced by Ercolania due to Baba & Hamatani’s (1970a) redescription of Stiller ornalus. Alderia harvardiensix is identical with A. moJesta which occurs in Finland, California, and Brazil, Hermaea cruciata is redescribed. It differs from //. coirala from Brazil. The substitution oiCargoa for Okenia is unnecessary. Craicna kaonwc Marcus, 1957, from Brazil is a synonym of C. pilata. TenelUa pallida is a junior synonym of T. adspersa (Nordmann, 1845). I was invited to visit the Chesapeake Biologi Europe conllrms that A. harvardiensis Gould, cal Laboratory (CBL) at Solomons, Maryland 1870, is identical with the European and during the fall of I for the purpose of Californian A. modesla (Loven, 1844). The assisting in the study of the nudihrancli, Brazilian A. uda (Marcus, l‘)56) can be consid Cratena pilala Gould. 'I'his slug was observed ered similarly. preying actively on the polyp stage of the One species from the present material was summer sea nellle, Chrysaora quinquccirrhi Dc classified by its shell as Acleun piauiusiriatns Sor. CBL is involved in a program of investiga (C. B. Adams, 1840), but the radula was found tion of tliis jellyrish, jointly sponsored by the to be different from Acteou and similar to University of Maryland, the United Stales Rictaxia Dali, IH71. Department of Commerce and the Slate of The syslematics of Calliopaea fiiscata Maryland under contract no. 14-17-0003-571. (Gould, 1870), now Ercoluniu fiiscatu. and While there I was afforded the opportunity Fmhk’toniu fuscaia (Gould, 1870) Jias utifoi tu- to collect and examine some opisthobranch nately been confused by Bergh (188(), note on species from the Chesapeake Bay. p. 1 I. 3.^, 37) and Chambers (1934; 609-610). The classification of the temperate we.stern Cory (1967; 84) did not classify his Hrnbleronia Atlantic opisthobranchs in faunal lists is gener to species. Therel'orc detailed descriptions and a ally based upon the original descriptions and modern bibliography of the present species of figures of Gould (1870). For some forms, this opisthobranchs are justified as a basis for future may be sufficient, e.g. there are probably only determinations. two species of hlysia. (nos. 0 and 10, below) which are easy to recognize and of restricted I. Rictaxis piiiu'toslriaii/s (C. B. Adams, 1840) range. However, comparison of the Alderia from Canada (Bieakney and Bailey. 1*^>67) and Tornatfl/a punciostriala. CJould. 1870: 224, I'i;;. 5)5. Aciacon puncloslrialiis. Pilsbry, 1893: 157, pt. 18, from Chesapeake Bay (no. 7) with those from figs. 98-99. pi. 19, figs. 22-2.3. Aciacon piincKisirialus. Piistiry, 1893: 157, pt. 18, fig. r. non Actcon punclaslrialux. - Marcus, ]95Sb: 'Submitted Nov. 1970; some additions 'une 1972. 32, figs. 1-10. table 1. Species of opisthobranchs considered in 2. Haminoea solitaria {Say. 1822) • his paper. Fig. 1 A-F :)rder Cephalaspidea Haminoea solilaria. Gould, 1870: 222, fig. 5 13. Pils- 1 . Rictaxis puncroslrialus (C. B. Adams, 1840) bry, 1893: 357, pi. 28, fig. 44, pi. 4 1 fig. 32. Abbott, 1955:279 pi. 26. fig. S. Smallwood, 1904. 2 . Haminoca solilaria (Say, 1822) Tigs. 1 A-F 3. Haminoea suciinea (Conrad, 1846) Figs. 2 A-I MATERIAL. Chesapeake Biological Labora 4. Acteocina canaticulata (Say, 1826) tory collection, August 1970,9 animals and 5 ^ )rder Ascoglossa empty shells. From Clioptank River, salinity 5. Ercolania fuscata (('lould, 1870) 1 1 o/oo. Further distribution, Massachusetts to 6 . Ercolania vaneHus (Marcus, 1957) I'ig. 3 A 7. AUeria moJcsla (Loven, 1844) l igs. 3 B-F Georgia. 8 . Hermaca cruciata ((iould, 1870) F'ig. 4 DESCRIPTION. The thin shells are ovoid, 9. h'lyxia chlorotica Gould, 1870 l igs. 5 A-D Iheir outlines are convex, and the greatest h'lysia calulus (Gould, 1870) I'igs. 6 A-F !0 . width is in front of the middle. The apex is Order Doridoideu 11. Doris verrucosa (l.inne, I 758) Fig. 7 A depressed and the spire perforate or closed by a 12. f’olyccrella coiiyna Marcus, 1957 Fig. 7 B callus. The sharp outer lip arises from the right 1.1. Okenia cupella (Vogel and Schull/, side of the perforation, rises higher than (he 1970) apex, and is rounded below. The inner lip is 14. DoridcHa ohscura Verrill, 1870 l igs. 7 C-F convex, the columella deeply concave, with a I.S. DoriopsiUa pharpa Marcus, 1959 Figs. 8 C-D Order 1 A)lidoido',i narrow, reflexed fold covered by an opaque l(). '['cncllia pallida (Alder and callus, which extends to the apex. The colorless Hancock, 1855) t ig. 8 E shell is transparent in life, whitish and .subpellu- 17. Cratcna pilata Gould, I 870 cid when dry. Ther' are ''out 150 spiral striae, which are deep fi:rrows narrower than their interspaces, often with indistinct ones in be MATERIAL. Maryland; Solomons, in an tween. The slightly depressed, irregular growth aquarium at the ('hesapeake Biological Labora lines over the entire length of the shell distort tory, September 1969, 8 animals and an empty the spiral grooves. The inner whorls are .slisll, three egg masses. Fkirida: Key Biscayne, reabsorbed. among algae on outer side of mangrove, The greenish flesh is stippled with melano- specimens, November 1970. phores in different density. The Hancock’s RKMARKS. The present specimens dilTer by organs are slightly wavy ridges. The jaw Iheii radula with the formula 5.0.5 I'roin elements are rhombic platelets with 4-9 pointed Acleon with many rows, each consisting of a denticles (fig. IB) quite different from the great number of unifomi teeth (Marcus, 1958b: numerous bead-like ones in //. cicgans (Fig. IG) Hence they must be assigned to the genus and H. antiHarum, but identical with those of Rictaxis Dali, 1871. The Brazilian species //. succinea (Fig. 2D). The radula iTieasures 1.0 published as Acteon puncloxrrialus Marcus X 0.8 mrn and has 21 rows with 29,1.29 teeth (I958b: 33) is a true Actcon and 1 name it A. (Fig. ID), siiTiilar to the teeth of //. succinea peiecais, spec. nov. Its diagnosis is: Shell solid, (Fig. 2F). The rhachidian tooth has about 10 with 5 -6 whorls, ratio length:width = I.Ol- denticles on either side, which occupy less of 1.73:1, aperlure 62-(-)6.5% of height. Sculpture the breadth than those of //. succinea. The ilal spiral striae separated by narrow punctuate gizzard teeth between the plates are brushes of !urrows in the lower third of the body whorl. spines, separate from the beginning; there is a Pallial caecum 1.5 whorls long; penial papilla ring of pigment cells around the base of each Miiooth. one, and a broader ring around the bundle. The The type specimen is a dry shell of 9.5 mm gizzard plates (Fig. IE) have about 15 arched ieighl. It is kept in the Department of ribs. Their sculpture is irregular, a row of big oologia, Instituto de Biociencias, University of knobs on the margin of each rib, and small 5o Paulo. Brazil. beads on the surface (Fig. IC). A study of the adult animal was published The inner reproductive organs correspond to ■ ter the present paper had been submitted the type described for Haminoea elegans (Mar Marcus, 1972: 170, figs. 1,6-10). cus, 1958b: 36-37, frg. 16), but the inner lobe I'ig. I. A-i'. Haminoea solitaria. A. Anterior part of preserved animal. B. Jaw plalelei.s. C. Border o f rib ol gizzard plate. D. Rhachidian tooth and lateral tooth from middle of half-row. E. Gizzard plate. 1-. Maie copulatory organ. G-H. Haminoea elcgans (Gray) from Brazil. G. Jaw plalelel.s. H. Border of rib of gizzard plal -. of the mucus gland is much longer and spiny area near its base. The seminal vesicle narrower than in elegans. The male atrium, covered with glandular papillae over the enti e when invaginated, lodges two soft papillae surface (Fig. IF). hanging into the lumen (Fig. IF). Its wall DISCUSSION. The present material v. iS contains an area with cuticular spines. Com received after 1 had completed the descripti' n pletely everted (Fig. 1 A) il is a hollow sac, 5.5 of the below mentioned specimens of j!- mm long and 2.6 mm wide, with the small, succinea. The animals of both species agree n of head shield and foot, Hancock’s organ than the smaller ones. Table 3 gives the specific arapodia, jaw platelets and radula. How- characters of the western Atlantic species of he lot of//, solitaria caught in August are Haminoea, as far as 1 can stale them, and shows bigger and have a stronger sculpture than that, apart from size, only the ratio of the shell succinea of September. The shells of //. differs between solitaria and succinea, so ea are cylindrical, while those of //, possibly succinea is a synonym oi' solitaria. ia are ovoid. Also, the proportions of the liffer: in the small //. succinea the ratio of 3.