Additions to the hydroids (Cnidaria, Hydrozoa) of the Bay of Fundy, northeastern North America, with a checklist of species reported from the region Author Calder, Dale R. text Zootaxa 2017 4256 1 1 86 journal article 33174 10.5281/zenodo.556851 10284664-323e-49f2-a19f-3ef15f718cc0 1175-5326 556851 985C0239-D00C-457D-B593-76A3081BCEEA Eudendrium bleakneyi , sp. nov. Figs. 13 b–d, 14, 15 Material examined. HOLOTYPE . NB: St. Croix River , St. Andrews , off Joe's Point , 45°04’30”N , 67°05’20”W , 16 m , scallop drag, 06.ix.1984 , several colony fragments, up to 11 mm high, with male gonophores, coll. D. Calder , ROMIZ B1473. PARATYPES . NB: St. Croix River , St. Andrews , off Joe's Point , 45°04’30”N , 67°05’20”W , 16 m , scallop drag, 06.ix.1984 , one colony, 1.1 mm high, with single blastostyle having two female gonophores, coll. D. Calder , ROMIZ B1381. NB: St. Croix River , St. Andrews , off Joe's Point , 45°04’30”N , 67°05’20”W , 16 m , scallop drag, 06.ix.1984 , one colony, 6 mm high, one blastostyle with male gonophores, coll. D. Calder , ROMIZ B1472. NB: St. Croix River , St. Andrews , off Joe's Point , 45°04’30”N , 67°05’20”W , 16 m , scallop drag, 06.ix.1984 , one colony, 5.5 mm high, without gonophores, coll. D. Calder , ROMIZ B1475. Etymology. The specific name honours Dr. J.S. Bleakney of Acadia University, an esteemed mentor who contributed greatly to the content of this work. FIGURE 14. Eudendrium bleakneyi , sp. nov. , paratype, ROMIZ B1472. a, hydranth, low magnification, darkfield. b, hydranth, medium magnification. c, hydranth, cleared, medium magnification, showing nematocyst band. d, male gonophores, low magnification, darkfield. e, tip of male gonophore, medium magnification, with nematocyst battery at tip. f, nematocyst battery, high magnification, showing arrangement of microbasic euryteles. Description. All parts of hydroid exceptionally minute. Colonies mostly erect, arising from a creeping hydrorhiza, reaching 11 mm high, occasional parts of colony bearing single pedicels. Hydrocaulus monosiphonic, contorted, sparsely and irregularly branched, about 0.05–0.09 mm in diameter, with branches resembling hydrocaulus. Perisarc thin, amber-coloured in older parts, clear in younger parts, covering all parts of colony except hydranth distal to perisarc groove, annulated at bases of hydrocauli, branches, and ultimate branchlets, with occasional wrinkles elsewhere but mostly smooth. Hydranths cup-shaped to tumbler-shaped, about 0.2 mm long from perisarc groove to hypostome, 0.1 mm wide at level of tentacles, with distinct perisarc groove basally and knob-shaped to flared hypostome distally. Tentacles solid, filiform, in one whorl, about 18–20 in number; tentacular nematocysts arranged obliquely. Base of hydranth immediately above perisarc groove with a variably elevated nematocyst belt containing an extraordinarily dense aggregation of microbasic euryteles. Nematophores absent. Nematocysts of tentacles, hypostome, and nematocyst belt comprising microbasic euryteles only. Colonies gonochoristic; gonophores fixed sporosacs arising from reduced hydranths. One tiny female colony with a single reduced hydranth having two gonophores, each gonophore with an unbranched, knobby spadix curving over egg, with knobs containing batteries of nematocysts. Male gonophores occurring in a cluster on reduced hydranths having no tentacles, such blastostyles bearing gonophores having 1–3 round to oval chambers, multiple chambers when present in a linear series, terminal chamber bearing a prominent cap or projection heavily armed with microbasic euryteles. Cnidome ( Fig. 15 ) Hydranths—microbasic euryteles (n = 4): 6.2–8.8 µm long × 2.6–3.1 µm wide (undischarged) Terminal nematocyst cap, male gonophores—microbasic euryteles (n = 10): 6.6–7.1 µm long × 2.0–2.5 µm wide (undischarged) Remarks. Species of the anthoathecate hydroid genus Eudendrium Ehrenberg, 1834 are readily distinguished by the characteristic morphology of their hydranths and gonophores. Hydranths are usually large and urn-shaped, with a perisarc groove basally, a single whorl of solid filiform tentacles near the distal end, and a prominent, knobshaped to flaring hypostome beyond. Gonophores arise at least initially from the gastric column of the hydranth, and are fixed sporosacs in all known species of the genus. With certain exceptions, those of the male are arranged in a linear series of bead-like chambers while those of the female consist of a spadix enveloping a single egg. Morphological and molecular evidence both support the hypothesis that the genus is monophyletic ( Marques , Peña Cantero et al . 2000 ; Moura et al . 2008 ). FIGURE 15. Eudendrium bleakneyi , sp. nov. , nematocysts, paratype, ROMIZ B1472. a, microbasic eurytele, from hydranth. b, microbasic eurytele, from hydranth, discharged. c, microbasic eurytele, from gonophore. Although the genus Eudendrium is highly distinctive, the numerous nominal species assigned to it can be exceedingly difficult to identify on the basis of morphology alone. Many of them were founded on sterile specimens or on unreliable characters, and are now considered species inquirendae . Characters accorded particular taxonomic importance include the structure of the gonophores, particularly those of the female, the extent of retrogression of reproductive hydranths, and more recently the complement, distribution, shape, and size of nematocysts ( Picard 1951 ; Watson 1985 ; Calder 1988 , 2010 ; Marques , Mergner et al . 2000 ; Marques , Peña Cantero et al . 2000 ; Puce et al . 2005 ; Bouillon et al . 2006 ; Schuchert 2008b ). Also perceived to be helpful in the identification of certain species is the presence or absence of buttons or a continuous band of nematocysts around the gastric column of the hydranth, the presence or absence of nematophores, the prominence of the perisarc groove on the hydranth, and the orientation of nematocysts on the tentacles, whether tending to be parallel or oblique to the tentacular axis ( Schuchert 2008b ). As for Eudendrium bleakneyi , sp. nov. , its diminutive colony size aligns it with a group of small species included within a so-called “ E. capillare group” (e.g., Watson 1985 ; Marques , Mergner et al . 2000 ). That group appears to be morphologically diverse, however, so comparisons were made here with all recognized species of the genus. Particular attention was given to the cnidome, although other morphological characters were considered as well. Within the genus Eudendrium , 73 nominal species are currently recognized as valid worldwide in WoRMS. With the identity of two of them ( E. attenuatum Allman, 1877 ; E. laxum Allman, 1877 ) being regarded as doubtful (e.g., Puce et al . 2005 ), 71 species were considered during this study in making comparisons with E. bleakneyi . Of these, 48 are distinctly different from the new species in having “complementary” nematocysts ( Table 2 ), a designation given to nematocysts in addition to small microbasic euryteles, which are believed to occur in all species of the genus. Therefore, these 48 need not be considered further here in relation to E. bleakneyi . Of the remaining 23 species, at least 11 resemble E. bleakneyi in having a cnidome comprising only small microbasic euryteles ( E. antarcticum Stechow, 1921b ; E. armatum Tichomiroff, 1887 ; E. capillare Alder, 1856a ; E. corrugatum Watson, 1985 ; E. deciduum Millard, 1957 ; E. deforme Hartlaub, 1905 ; E. japonicum Yamada, 1954 ; E. nambuccense Watson, 1985 ; E. pennycuikae Watson, 1985 ; E. terranovae Watson, 1985 ; E. vervoorti Marques & Migotto, 1998 ). However, all of these species differ from E. bleakneyi in one or more morphological characters. For example, a prominent nematocyst belt, such as that encircling the base of the hydranth in E. bleakneyi , is lacking in all except E. nambuccense and possibly E. antarcticum ( Millard 1975 ; Watson 1985 , 2003; Hirohito 1988; Marques , Mergner et al . 2000 ; Schuchert 2008b ). Moreover, unlike in E. bleakneyi , colonies of E. armatum , E. corrugatum , E. deciduum , and E. terranovae are relatively large and polysiphonic ( Millard 1975 ; Watson 1985 ; Schuchert 2008b ). Other noteworthy differences from E. bleakneyi include the presence of nematophores in E. armatum and E. japonicum (Hirohito 1988; Schuchert 2008b ), the existence of a branched spadix in E. deciduum ( Millard 1957 , 1975 ); the lack of a spadix over the ovum in E. vervoorti ( Marques & Migotto 1998 ) , and the paired chains of chambers in male gonophores of E. deforme (Watson 2003) . Notably too, some colonies of E. capillare have complementary nematocysts in the form of small isorhizas ( Schuchert 2008b ). Eudendrium bleakneyi is very close in morphology to E. nambuccense , differing from the original account of that species ( Watson 1985 ) in: (1) being sparsely rather than profusely branched, (2) having small microbasic euryteles that are proportionally more slender, (3) having at least some male gonophores with two chambers rather than a single one, (4) having female gonophores on atrophied rather than on partially atrophied hydranths, (5) having hydranths with about 18–20 rather than 24–28 tentacles. Meanwhile, it is unclear from existing descriptions and illustrations whether a nematocyst belt exists in E. antarcticum , although it seems possible (see Marques , Mergner et al . 2000 : fig. 9). Nevertheless, that species differs from E. bleakneyi in having female gonophores arising from hydranths that are little if at all reduced ( Stechow 1921b , 1925 ). The cnidomes of the remaining 12 species are currently undescribed. Of primary interest in this heterogeneous group is the identity of E. cingulatum Stimpson, 1853 , unreported since its original description from Bay of Fundy at Grand Manan Island, NB. Stimpson’s (1853) account of the species was lacking in detail, and no illustration was provided. Fraser (1918) thought it might be identical with E. annulatum Norman, 1864 , but later simply questioned its validity ( Fraser 1944 , 1947a ). Earlier, A. Agassiz (1865) had included it, with question, in the synonymy of Bougainvillia superciliaris ( L. Agassiz, 1850 ) . The hydroid was described by Stimpson as “small,” but no measurements were given. There was no indication that his colonies were fertile, and gonophores of the species remain unknown. The specific name cingulatum , meaning “belted” or “girdled,” is intriguing. While it might refer to a belt of nematocysts on the hydranths, such as that found in E. bleakneyi and certain other species of the genus, Stimpson provided no explanation for his choice of the name, and it is unknown what character the Latin adjective was describing. His species seems to differ from E. bleakneyi in colony form, with branches “…somewhat as in E. rameum …” rather than being sparsely branched or stolonal, and in having pedicels that were strongly annulated, sometimes completely so, rather than being mostly smooth beyond the base. No record of the species was found in a search of online catalogues of the MCZ, NMNH, or YPM, and no type is known to exist. Eudendrium cingulatum is regarded here as a nomen dubium . None of the other species included in the genus appear from their descriptions to match E. bleakneyi . In the size and habit of their colonies, only two ( E. irregulare Fraser, 1922 ; E. rugosum Fraser, 1940 ) resemble this new species. Those of the remainder ( E. armstrongi Stechow, 1909 ; E. caricum Jäderholm, 1908 ; E. certicaule Fraser, 1938a ; E. cochleatum Allman, 1877 ; E. dispar L. Agassiz, 1862 ; E. distichum S.F. Clarke, 1879 ; E. maldivense Borradaile, 1905 ; E. nodosum Fraser, 1938a ; E. speciosum Fraser, 1945 ) differ in having colonies that are larger and more branched. Other reported differences setting these species apart include (1) the occurrence, on nonaborted hydranths, of male and female gonophores in E. certicaule and E. dispar , and of male gonophores in E. maldivense and E. speciosum ; (2) the presence of oblique annulations at the bases of stems and branches in E. cochleatum ; (3) the existence of nodes at irregular intervals on stems and branches in E. nodosum ( L. Agassiz 1862 ; Allman 1877 ; Borradaile 1905 ; Fraser 1938a , 1945 ). Finally, stems and branches of E. irregulare differ from those of E. bleakneyi in having occasional wrinkles but no annulations ( Fraser 1922 ), while those of E. rugosum differ in being strongly wrinkled throughout ( Fraser 1940 ). Nine species of Eudendrium have been reported from the Bay of Fundy (see Appendix 1), with two of those ( E. cingulatum Stimpson, 1853 ; E. tenellum Allman, 1877 ) regarded as species inquirendae . Eudendrium bleakneyi , described as new here, is added as a tenth species from the bay. Microbasic euryteles borne on nematocyst caps of the male gonophores of this species appeared to be slightly smaller and more slender than those of the tentacles and nematocyst ring on the hydranth. Eudendrium bleakneyi was dredged during late summer ( 06 September 1984 ) in relatively shallow waters ( 16 m ) from a commercial scallop [( Placopecten magellanicus ( Gmelin, 1791 ) ] ground in the St. Croix River off St. Andrews, NB. Salinities in that region of the estuary are typically in the polyhaline range (18–30‰), and water temperatures that time of year are normally between 10–15° C (personal observations). TABLE 2 . Species of Eudendrium Ehrenberg, 1834 listed as valid in WoRMS (early 2016), with information on complementary nematocysts from one or more primary references. Also included is E. bleakneyi , sp. nov. , described herein. Excluded are two species in the WoRMS list ( E. attenuatum Allman, 1877 ; E. laxum Allman, 1877 ) that have been considered species inquirendae (Puce et al . 2005). Small microbasic euryteles, believed to be part of the cnidome of all species of the genus, are not mentioned here. Criteria used distinguishing microbasic and macrobasic euryteles may be inconsistent from one author to another.

Species	Type Locality	Complementary Nematocysts	Reference
E. album Nutting, 1896 E. angustum Warren, 1908	UK: Plymouth South Africa: Algoa Bay	large macrobasic euryteles large unidentified nematocysts1	Schuchert 2008b Millard 1975
E. annulatum Norman, 1864	UK: Shetland Is.	large microbasic euryteles	Schuchert 2008b
E. antarcticum Stechow, 1921b	Bouvet Is.	absent	Peña Cantero & Gili 2006
E. arbuscula Wright, 1859	UK: Queensferry	large microbasic euryteles	Schuchert 2008b
E. armatum Tichomiroff, 1887 E. armstrongi Stechow, 1909	Mediterranean Sea India and Myanmar	absent cnidome undescribed	Schuchert 2008b
E. aylingae Watson, 1985 E. balei Watson, 1985	AUS: Great Detached Reef AUS: Western Port	large macrobasic euryteles large microbasic mastigophores	Watson 1985; Puce et al . 2006 Watson 1985
E. bathyalis Marques & Calder, 2000	Bermuda: Hungry Bay Bight	large microbasic euryteles	Marques & Calder 2000
E. bentart Peña Cantero, 2013	Low Is. (Southern Ocean)	large (?) isorhizas	Peña Cantero 2013
E. bermudense Calder, 1988	Bermuda: Hamilton Parish	large macrobasic euryteles	Calder 1988
E. biseriale Fraser, 1935	Japan: Sagami Bay	large bean-shaped nematocysts	Hirohito 1988
E. bleakneyi , sp. nov. E. boreale Yamada, 1954 E. breve Fraser, 1938a	Canada: St. Andrews, NB Japan: Hokkaido Ecuador: Galápagos Is.	absent large (& medium) microbasic euryteles large isorhizas2	described herein Kubota 1976 Cooke 1975
E. calceolatum Motz-Kossowska, 1905	France: Banyuls-sur-Mer	large microbasic euryteles	Schuchert 2008b
E. californicum Torrey, 1902	USA: California	large microbasic euryteles	Weill 1934
E. capillare Alder, 1856a	UK: Embleton Bay	absent, or with small isorhizas	Schuchert 2008b
E. capillaroides Schuchert 2008b	France: Baie de Morlaix	medium microbasic euryteles	Schuchert 2008b
E. caraiuru Marques & Oliveira, 2003 E. caricum Jäderholm, 1908	Brazil: São Sebastião Russia: Arctic seas	large mesobasic euryteles cnidome undescribed	Marques & Oliveira 2003
E. carneum S.F. Clarke, 1882 E. certicaule Fraser, 1938a	USA: Hampton Roads, VA Ecuador: Galápagos Is.	large heterotrichous anisorhizas cnidome undescribed	Calder 1988
E. cingulatum Stimpson, 1853	Canada: Grand Manan Is.	cnidome undescribed
E. cnidoferum Stechow, 1919	Sweden: Bohuslän	large macrobasic euryteles	Schuchert 2008b
E. cochleatum Allman, 1877 E. corrugatum Watson, 1985	USA: Cape Fear, NC AUS: N Stradbroke Is.	cnidome undescribed absent	Watson 1985

……continued on the next page ……continued on the next page Complementary nematocysts of Eudendrium angustum Warren, 1908 were thought by Millard (1975) to be either macrobasic euryteles or isorhizas, and not microbasic euryteles. Puce et al . (2005) regarded them as large microbasic euryteles. TABLE 2. (Continued)

Species	Type Locality	Complementary Nematocysts	Reference
E. currumbense Watson, 1985	AUS: Currumbin	large (?) macrobasic euryteles	Watson 1985
E. cyathiferum Jäderholm, 1904	South Georgia	large euryteles	Watson 2003
E. deciduum Millard, 1957	South Africa: False Bay	absent	Millard 1975
E. deforme Hartlaub, 1905 E. dispar L. Agassiz, 1862 E. distichum S.F. Clarke, 1879	Chile: Calbuco USA: Massachusetts Mexico: Isla Holbox4	absent large microbasic euryteles3 cnidome undescribed	Watson 2003 described herein
E. exiguum Allman, 1877	USA: Florida Reef	present; category undetermined	Puce et al . 2005
E. eximium Allman, 1877	USA: Florida Reef	large microbasic euryteles	Puce et al . 2005
E. fruticosum Allman, 1877	USA: Key West, FL	large microbasic euryteles	Puce et al . 2005
E. garis Puce et al ., 2006	Indonesia: Siladen	large microbasic euryteles	Puce et al . 2006
E. generale von Lendenfeld, 1885b	AUS: Port Phillip Bay	large microbasic euryteles	Watson 1985
E. glomeratum Picard, 1952	France: Banyuls-sur-Mer	large macrobasic euryteles	Schuchert 2008b
E. infundibuliforme Kirkpatrick, 1890 E. irregulare Fraser, 1922	AUS: NNW of Warrior Is. Canada: near Gabriola, BC	large macrobasic euryteles & small (?) macrobasic euryteles cnidome undescribed	Watson 1985
E. jaederholmi Puce et al ., 2002	South Georgia	large unidentifiable nematocysts	Puce et al . 2002
E. japonicum Yamada, 1954	Japan: Sagami Bay	absent	Hirohito 1988
E. kirkpatricki Watson, 1985	AUS: Murray Is.	large microbasic euryteles	Watson 1985
E. klausi Puce et al ., 2005	Belize: Carrie Bow Cay	large microbasic euryteles	Puce et al . 2005
E. macquariensis Watson, 2003	Macquarie Is.	unidentified bean-shaped capsules	Watson 2003
E. magnificum Yamada, 1954	Japan: Sagami Bay	large unidentified nematocysts	Hirohito 1988
E. maldivense Borradaile, 1905	Maldives	cnidome undescribed
E. maorianus Schuchert, 1996	New Zealand: Wellington	medium microbasic euryteles	Schuchert 1996
E. merulum Watson, 1985	AUS: S of Clonmel Is.	large microbasic euryteles	Watson 1985
E. minutum Watson, 1985	AUS: Port Phillip Heads	medium & large microbasic euryteles	Watson 1985
E. moulouyensis Marques, Peña Cantero & Vervoort, 2000 E. mucronatum Billard, 1926 E. nambuccense Watson, 1985	Morocco: Chafarinas Is. Egypt: Suez Canal AUS: Nambucca Heads	large microbasic euryteles (?) atrichous anisorhizas absent5	Schuchert 2008b Marques, Peña Cantero & Vervoort 2000 Watson 1985
E. nodosum Fraser, 1938a	Ecuador: off Santa Elena	cnidome undescribed

TABLE 2. (Continued)

Species	Type Locality	Complementary Nematocysts	Reference
E. novaezelandiae Marktanner- Turneretscher, 1890 E. pennycuikae Watson, 1985 E. pocaruquarum Marques, 1995	New Zealand: Auckland AUS: Bundaberg Brazil: São Sebastião	large & medium microbasic euryteles absent large microbasic euryteles	Schuchert 1996 Watson 1985 Marques 1995
E. racemosum (Cavolini, 1785)	Italy: Golfo di Napoli	small isorhizas	Schuchert 2008b
E. rameum (Pallas, 1766)	Mediterranean Sea	large microbasic euryteles	Schuchert 2008b
E. ramosum (Linnaeus, 1758)	UK: Whitstable, Kent	large microbasic euryteles	Schuchert 2008b
E. ritchiei Millard, 1975 E. rugosum Fraser, 1940 E. scotti Puce et al ., 2002	South Africa: Cape Town Flemish Cap, North Atlantic Antarctica: Tethys Bay	large mesobasic euryteles cnidome undescribed large macrobasic euryteles	Millard 1975; Schuchert 1996 Puce et al . 2002
E. simplex Pieper, 1884 E. speciosum Fraser, 1945	Croatia: Dalmatian coast USA: Pensacola, FL	large macrobasic euryteles cnidome undescribed	Schuchert 2008b
E. terranovae Watson, 1985	New Zealand: North Cape	absent	Watson 1985; Schuchert 1996
E. tottoni Stechow, 1932 E. unispirum Schuchert 2008b E. vaginatum Allman, 1863 E. vervoorti Marques & Migotto, 1998	Antarctica: McMurdo Sound UK: Plymouth UK: Shetland Is. The Netherlands: Zeeland	unspecified nematocyst category large microbasic euryteles large microbasic euryteles absent	Marques & Migotto 1998 Schuchert 2008b Schuchert 2008b Marques & Migotto 1998

Cooke (1975) regarded specimens examined by him as questionably referable to Eudendrium breve . The cnidome of Eudendrium dispar was examined during this study in syntype material from Nahant, Massachusetts (MCZ COEL 34). Complementary nematocysts, in a band around the base of the hydranth, were large microbasic heteronemes, most likely microbasic euryteles. The collection locality of Eudendrium distichum was said by S.F. Clarke (1879) to be “Ten miles north of Zoblos Island . ” “ Zoblos Island ” was taken to be Holbox Island, Mexico , Calder (2013: 59). According to Watson (1985) , microbasic euryteles on gonophores of E. nambuccense are slightly larger than those on hydranths.