Eurypon oxychaetum, Cavalcanti & Santos & Pinheiro, 2018

Cavalcanti, Thaynã, Santos, George Garcia & Pinheiro, Ulisses, 2018, Description of three species of Eurypon Gray, 1867 (Raspailiidae: Demospongiae: Porifera) from the Western Atlantic and a name to replace the the secondary homonym Eurypon topsenti, Zootaxa 4388 (1), pp. 89-101: 91-93

publication ID

https://doi.org/10.11646/zootaxa.4388.1.6

publication LSID

lsid:zoobank.org:pub:51239FBF-CE7E-4614-9E18-3D78F489B16C

persistent identifier

http://treatment.plazi.org/id/039687F1-FFEA-FFA9-FF6A-07C89549FC07

treatment provided by

Plazi

scientific name

Eurypon oxychaetum
status

sp. nov.

Eurypon oxychaetum   sp. nov. ( Figures 1–3 View FIGURE 1 View FIGURE2 View FIGURE 3 , Table 1)

Type locality: Brazil, Paraíba State.  

Type specimens: Holotype. UFPEPOR 3007, off Conde Municipality (07° 21' S – 034° 38' W), Paraíba State, Brazil, depth 30 m, st. 20, Algas Project (01/VII/1969) GoogleMaps   . Paratype. UFPEPOR 3023 and UFPEPOR 3026, off Pitimbu Municipality (07° 30' S – 034° 45' W), Paraíba State, Brazil, depth 10 m, st. 28, Algas Project (06/X/1969) GoogleMaps   .

Diagnosis. Eurypon   with large subtylostyles (1025–2125 / 13–39 µm), subectosomal styles (283–412 / 2–5 µm), two categories of acanthostyles (I = 290–650 / 13–26; II = 68–135 / 3–6 µm, length / width) and oxychaetes (77–119 µm).

External morphology ( Fig. 2A –B View FIGURE2 ). Thinly encrusting sponge, 0.5–1.0 mm thick. Projecting spicules through surface. Consistency is fragile. Oscula were not found. Colour is beige (preserved in ethanol 80 %), colour in vivo unknown.

Skeleton ( Fig. 2C View FIGURE2 ). No special ectosomal skeleton. Choanosomal skeletal arrangement microcionid. Dense basal layer echinated by subtylostyles and acanthostyles protruding through surface. Styles and oxychaetes dispersed in the subectosomal region.

Spicules ( Fig. 3A –J View FIGURE 3 ). Choanosomal subtylostyles, occasionally tylostyles (1025– 1727.5 –2125 / 13– 24.4 –39 µm): long, thin, smooth, curved and blunt tips ( Fig. 3A –B View FIGURE 3 ); Subectosomal styles (283– 354.5 –412 / 2– 3.2 –5): thin, smooth and curved ( Fig. 3C –D View FIGURE 3 ); Acanthostyles I (290– 426.5 –650 / 13– 19.6 –26 µm): robust, slightly curved, and with few curved spines over the shaft directed to the base ( Fig. 3G –H View FIGURE 3 ); Acanthostyles II (68– 97.9 –135 / 3– 4.9 –6 µm): small, thin, straight to slightly curved, abundant curved spines directed to the base ( Fig. 3I –J View FIGURE 3 ); Oxychaetes (77– 100.8 –119): small, straight and with of spines over the whole shaft ( Fig. 3E –F View FIGURE 3 ).

Distribution and ecology ( Fig. 1 View FIGURE 1 ). Brazil: Northeastern Region: Paraíba State, between 10– 30 m. Found on calcareous algae during a historical expedition at Paraíba State in 1969.

Etymology. The specific epithet oxychaetum   refers to the presence of oxychaete spicules, exclusive of the new species.

Remarks. Eurypon oxychaetum   sp. nov. is characterized for possessing a spicule complement composed by tylostyles, styles, acanthostyles in two size categories, oxychaetes and an encrusting growth form. The most similar species are E. clavilectuarium   and E. suassunai   which share two categories of acanthostyles, subectosomal styles and choanosomal subtylostyles but they differ from the new species for presenting raphideform styles and spicules dimensions (Tab. 1). The new species is distinguished from E. clavatella Little, 1963   , E. clavatum ( Bowerbank, 1866)   , E. coronula ( Bowerbank, 1874)   , E. distyli   , E. fulvum Lévi, 1969   , E. lacazei (Topsent, 1891)   , E. longispiculum ( Carter, 1876)   , E. major Sarà & Siribelli, 1960   , E. pulitzeri   nom. nov., E. radiatum ( Bowerbank, 1866)   , E. toureti ( Topsent, 1894)   and E. viride ( Topsent, 1889)   because these species have only one category of acanthostyles. In the species E. lictor ( Topsent, 1904)   and E. topsenti ( Burton, 1954)   acanthostyles are absent. E. oxychaetum   sp. nov. differ from E. hispidulum ( Topsent, 1904)   , E. incipiens Topsent, 1927   , E. mucronale ( Topsent, 1928)   , E. scabiosum ( Topsent, 1927)   , E. simplex ( Bowerbank, 1874)   and E. urizae (Hooper, 1996)   , because they do not have subectosomal styles. Eurypon miniaceum Thiele, 1905   and E. mixtum ( Topsent, 1928)   are distinguished from E. oxychaetum   sp. nov. by their spicules dimensions (Tab.1).