Amphimedon nodosa ( Linnaeus, 1759 )

Van Soest, Rob W. M., 2025, Typification of Porifera described in the 10 edition of Linnaeus’ Systema Naturae, volume II, 1759, Zootaxa 5638 (1), pp. 1-65 : 17-21

Amphimedon nodosa ( Linnaeus, 1759)

Figs. 8A–H , 9A–C

Spongia nodosa Linnaeus, 1759: 1348 , sp. 3; Linnaeus 1767: 1298, sp. 11; Gmelin in Linnaeus 1791: 3821, sp. 11. Spongia rubens Pallas, 1766: 389 , sp. 238 (in part, not: references of Imperato and Mercati, cf. below; also Boddaert 1768: 491 and Wilkens 1787: 226); Duchassaing & Michelotti 1864: 41, pl. X fig. 1.

Pachychalina rubens ; Schmidt 1870: 37; Wilson 1902: 392.

Chalina rubens ; Carter 1882: 275.

Haliclona rubens ; De Laubenfels 1936: 40, pl. 7 fig. 2, pl. 8 fig. 1; Burton 1954: 223; Hartman 1955: 167; Little 1963: 39; Hechtel 1965: 18; Pomponi 1976: 220; Green 1977: 86, fig. 7.

Amphimedon compressa Duchassaing & Michelotti, 1864: 78 , pl. XVII fig. 2; Van Soest 1980: 26, pl. III figs 24, pl. IV figs 12, text-fig. 9.

Haliclona (Amphimedon) compressa ; Wiedenmayer 1977: 82, pl. 12 figs 3–4, text-fig. 112.

Original description: ‘ Spongia scabra ramosa tenacissima: ramis nodosis perforatis’ (i.e. a rough branched sponge very tenacious (firm): knotty branches perforated).

Type material: Unknown. I propose as neotype RMNH POR. 11886 (field nr. MDB086 ), collected by Esther van der Ent and Nicole de Voogd at Martinique, Pointe Lézarde, 14.4833°N 61.0833°W, depth 19.2 m on September 7, 2016. Martinique is situated in the Caribbean which undoubtedly belongs to ‘ Mare Americanum’ as locality mentioned by Pallas and Linnaeus .

Molecular sequences: 28SrRNA, COI and 18SrRNA sequences were obtained by Niels van der Windt for this study.

Remarks: Linnaeus (1759) gave no references, but his definition was copied from Van Royen (1740: 522), who gave only one reference: Boerhaave Lugd. p. 9 (sp. 15) with description ‘ Spongia dura ramosa nigra suberis instar’ (i.e. a hard cork-like branched black sponge). Linnaeus (1753b: 1170, sp. 3) featured the same definition as Van Royen and Linnaeus (1759), with locality given as ‘Mari australi’. It is not clear where this locality was taken from, possibly from Boerhaave (1727). It may be interpreted as “Australian Seas’ (less likely because the continent was not named as such until the 19 th century) or ‘Southern Seas’ (the likely meaning, but it is uncertain what this then would encompass, e.g. Mediterranean, Caribbean, or Indian Ocean). There are no images for Van Royen’s and Linnaeus’ references.

Pallas (1766: 389, sp. 238, see also Boddaert (1768: 491) and Wilkens (1787: 226, fig. 73, reproduced here as Fig. 8E ) reassigned Linnaeus’ name under his new species Spongia rubens and also changed the locality into ‘Mare Americanum’. His definition of the species is: ‘ Spongia subramosa difformis mollis, poris majusculis sparsis’ (i.e. a soft subbranched sponge, scattered with large pores). This definition was followed by descriptive remarks concerning colour (grey-reddish or white) and branches that were thicker and coarser than those of Spongia oculata .

He also emphasized the firm consistency and large oscules. He gave four pre-Linnaean references (cf. also below), some of which in his opinion provided good representations of the species: Imperato (1599: 733, as ‘Alcyonio foraminosa’, no origin mentioned, reproduced here as Fig. 8A ); Sloane (1707: 63, pl. 23 fig. 5 from Jamaica, as ‘ Spongia minor & mollior medulla panis similis fibris tenuissimus’, meaning the sponge is smaller and softer, and inside it has bread-like fibers, here reproduced as Fig. 8B ); Mercati (1719: 106, as ‘Alcyonio de Tertio Quinti Generis’, no origin mentioned, here reproduced as Fig. 8C ); and Seba [1758: pl. 96 fig. 2 ‘ Spongia rigida ramosa ramis foraminulentis & nodosis’ (i.e. a rigid knotty branched sponge with openings, here reproduced as Fig. 8D )]. His list of references included Linnaeus’ (1759) Spongia nodosa , but he refrained from mentioning Van Royen and Boerhaave. He did not explain why Linnaeus’ name nodosa was replaced.

The name nodosa was not adopted by subsequent post-1766 authors other than Linnaeus himself ( Linnaeus 1767: 1298 and Gmelin in Linnaeus 1791: 3821), who listed Pallas’ Spongia rubens as a synonym of nodosa . However, Linnaeus did take over Pallas’ colour of grey-red and the locality of ‘Oceano americano’, abandoning the black colour and the ‘Mari australi’ origin cited in Linnaeus 1753. Subsequent authors invariably used Pallas’ Spongia rubens as the valid species name, starting with Duchassaing & Michelotti (1864), followed by Schmidt (1870), Carter (1882), Wilson (1902), De Laubenfels (1936), Burton (1954), Hartman (1955), Little (1963) and Hechtel (1965). If Spongia nodosa was a ‘forgotten’ species name (nomen oblitum), the name Spongia rubens could - perhaps - have been proposed to be eligible for reversal of precedence (ICZN art. 23.9) making Pallas’ name the nomen protectum. However, Wiedenmayer (1977: 82–83) adopted a different course. He discussed the present species in his attempt to justify his reassignment of specimens named Spongia rubens sensu Duchassaing & Michelotti (1864) to Haliclona (Amphimedon) compressa , currently Amphimedon compressa Duchassaing & Michelotti (1864) (see also Van Soest 1980: 26–29). Wiedenmayer emphasized that Pallas’ references of his Spongia rubens were not conspecific with what 20 th century authors assumed to be Haliclona rubens , because Imperato’s and Mercati’s (see Figs 8A and C ) images in his view strongly looked like what currently is considered Cribrochalina dura ( Wilson, 1902) from the Caribbean, or – if these images were taken from Mediterranean specimens which is likely – Petrosia ficiformis ( Poiret, 1789) or P. clavata ( Esper, 1794) (my own view). Nevertheless, Sloane’s image (see Fig. 8B ) from Jamaica could perhaps be Callyspongia tenerrima Duchassaing & Michelotti (1864) (Wiedenmayer’s suggestion) or Amphimedon compressa Duchassaing & Michelotti, 1864 (my suggestion). Wiedenmayer’s view that Seba’s (see Fig. 8D ) and Wilkens’ ( Fig. 8E ) images likely represent Agelas sceptrum ( Lamarck, 1814) or Agelas cervicornis ( Schmidt, 1870) is possible, but not certain, because conspecificity with what is currently named Amphimedon compressa is equally possible. Thus, we have a situation that Spongia nodosa / rubens is certainly multi-interpretable. In his capacity as First Revisor, Wiedenmayer could have selected a neotype for Spongia nodosa and/or a neotype for Spongia rubens to definitively solve the identity of the species. He did not do so, because he considered these names nomina dubia, which were in his opinion not eligible for type designations. However, the Code of the ICZN does not forbid choosing a neotype for an available name, which appears to have no extant type specimen, as is the case for Spongia nodosa and Spongia rubens .

The conclusion I draw from the above-described references is that it is a ramose sponge with firm consistency and reddish colour, with the origin uncertain but likely from the Central West Atlantic region because the only concrete geographic locality is Sloane’s record from Jamaica. The identity of this so far has not been agreed upon. His figure could be interpreted as a rather thinly developed specimen of what was considered Haliclona rubens by most 20th century authors, even though Wiedenmayer thought it could be Callyspongia tenerrima , a species of which no type material is extant ( Van Soest et al. 1983: 195). I can see no compelling reason to dispute that the type locality in the Central West Atlantic is correct, and thus there is no good reason to replace rubens sensu Duchassaing & Michelotti (1864: 41 , pl. X fig. 1) by Amphimedon compressa Duchassaing & Michelotti, 1864: 78 , pl. 17 fig. 2) as Wiedenmayer did, followed by most contemporaneous and current authors. Duchassaing & Michelotti’s specimens (see Van Soest et al. 1983) of Spongia rubens are still extant (ZMA Por. 02254 and Torino Museum MZUT Por. 106, and fragments thereof in MNHN (D.NBE. 1336) and in the Natural History Museum London, BMNH 1928.11.12.68), and a re-description and photo of the ZMA specimen (collected by P. Duchassaing at St. Thomas, U.S. Virgin Islands, approximate coordinates 18.3333°N 64.9333°W) is provided by Van Soest 1980: 27, pl. III fig. 4, here reproduced in Fig. 8F , making Spongia rubens recognizable. However, the status of Spongia nodosa as the senior synonym still must be addressed. The name is unused in the 19th and 20th century (the name was mentioned in the 20th century by De Laubenfels 1948: 21 and Wiedenmayer 1977: 83 for reasons of making the case for a nomen inquirendum or a nomen dubium, and this is not ‘prevailing usage’ in the sense of ICZN art. 23.9). Replacing the name Spongia nodosa with Spongia rubens by Pallas was not proposed at the time, and the rule of Priority (ICZN art. 23.1) is here invoked to propose Spongia nodosa Linnaeus, 1759 as the senior synonym in accordance with Linnaeus (1767) and Gmelin in Linnaeus (1791). A possible alternative would seem to be adopting ICZN art. 75.5 by assigning nomen dubium status to Spongia nodosa L. and Spongia rubens Pallas and requesting nomen protectum status for Amphimedon compressa . I believe this is not warranted in view of the persistent use of Haliclona rubens after 1899. The species needs an unequivocal type specimen in the form of a neotype proposed above. Through this choice the recognition of the species is guaranteed by in situ and on deck photos and molecular sequence information.

Species diagnosis: (after Van Soest 1980: 26, pl. III figs 24, pl. IV figs 12, text-fig. 9 as Amphimedon compressa ). Ramose to thickly flabelliform, up to 45 cm in height. Flabelliform shapes are the result of (partly) merging branches. Branches usually slightly knotty, not straight, approximately 1–2.5 cm diameter with rounded endings, with rows or more irregularly distributed oscules, with slight raised rims, of 2–8 mm in diameter. In flabelliform specimens oscula occur also on the upper rim. Colour pinkish to greyish and brownish red, both in situ, on deck and in alcohol (although this may become dull and greyish beige over time). Surface optically smooth, microhispid, occasionally rather bumpy. Consistency firm. There is no clear ectosomal tangential skeleton, but a rather tight three-dimensional subectosomal reticulum of spicule tracts is usually present forming rather regular small meshes. The choanosomal skeleton consists of a tight-meshed system of thick spicule tracts bounded by ample spongin, which however leave large (approximately 1 mm sized) open spaces. Ascending spicule tracts are 30–110 µm (2–12 spicules) in diameter, connecting tracts usually thinner. Spicules are robust oxeas, rarely with one or both apices rounded, 116–174 x 2–8 µm.

Amphimedon compressa Duchassaing & Michelotti, 1864 is the type species of Amphimedon (subsequent designation by De Laubenfels 1936: 45). This is here proposed to be a junior synonym of Amphimedon nodosa (L.).

A photo of an on-deck example from Belize is provided in Fig. 8G . In situ and on-deck images of the neotype specimen are provided in Figs 9A–C .

Distribution: ( Fig. 8H ) Greater Caribbean and Gulf of Mexico, North East Brazil ( De Voogd et al. 2023)

Figures

FIGURE 8. A–G, Images assigned to Amphimedon nodosa by various authors (originally mostly as Spongia). A. Imperato’s ‘Alcyonio foraminosa’ (1599: 733); B. Sloane’s ‘Spongia minor & mollior medulla panis similis fibris tenuissimus’ (1707: 63, pl. 23 fig. 5 from Jamaica); C. Mercati’s ‘Alcyonio de Tertio Quinti Generis’ (1719: 106); D. Seba’s ‘Spongia rigida ramosa ramis foraminulentis & nodosis’ (1758: pl. 96 fig. 2); E. Wilkens’ ‘Knotenschwamm’ (= knotty sponge) (1787: 226, fig. 73); F. Duchassaing & Michelotti’s Spongia rubens (1864: 41, specimen ZMA Por. 02254, from St. Thomas); G. unregistered ‘on deck’ specimen collected during the Belize Mangrove Sponge Workshop 1997 (see Rützler et al. 2000 as A. compressa, photo R. van Soest); H. distribution records of Amphimedon nodosa (L.), dots are WPD data, squares are OBIS data (image downloaded from the World Porifera Database, cf. De Voogd et al. 2023, as Amphimedon compressa).

FIGURE 9. Neotype of Amphimedon nodosa (Linnaeus, 1759 as Spongia) from Martinique, designated herein.A. in situ photo, courtesy Esther van der Ent; B. preserved neotype, photo R. van Soest; C. on deck photo by Nicole de Voogd.