Exsuperantia archipelagus

Carvalho, Francisca C. & Pisera, Andrzej, 2019, Revision of the genus Exsuperantia Özdikmen, 2009 (Tetractinellida: Phymaraphiniidae) with description of a new species from the Atlantic Ocean, Zootaxa 4613 (1), pp. 135-151: 140-141

publication ID

https://doi.org/10.11646/zootaxa.4613.1.7

publication LSID

lsid:zoobank.org:pub:6E25D4D4-00EF-4D37-B701-8509FBD645DD

persistent identifier

http://treatment.plazi.org/id/6C499E3A-FFD6-9B00-17AB-B6E3EF9DF94E

treatment provided by

Plazi

scientific name

Exsuperantia archipelagus
status

sp. nov.

Exsuperantia archipelagus  sp. nov.

Figures 1View FIGURE 1 –4; Table 3

urn:lsid:zoobank.org:act:7ADC8D28-86CF-446F-A3AD-E33B6822125D

Synonymy. Racodiscula clava sensu Topsent (1892  , 1904, 1928); Exsuperantia  sp. Carvalho et al. (2015).

Type locality. Terceira island, Azores archipelago, Portugal.

Type material. Holotype. MNHN DT- 782/1 (dry specimen), locality: Terceira island, Azores archipelago, Por- tugal (38º52’50’’N, 27º23’05’’W), depth: 599 m.GoogleMaps  Paratypes. MNHN DT- 782/2 (dry specimen), locality: Terceira island, Azores archipelago, Portugal (38º52’50’’N, 27º23’05’’W) depth: 599 mGoogleMaps  ; DOP1976 (specimen preserved in 90% ethanol), locality: Azores Bank, Azores archipelago, Portugal (38º05’59’’N, 29º08’59’’W), 168–594 m depth.GoogleMaps 

Additional material. Exsuperantia archipelagus  sp. nov.: DOP 5883/6212/6248/6255, Azores archipelago; HBOM 003:02023 (BMR 29-V-91 -3-003), Madeira, HBOM 003:00660 (BMR 09-VI-91 -4-008), Canaries (see table 1 for more details).

Comparative material examined. Exsuperantia clava Schmidt 1879  — Syntype MCZ 6436 (orig. 275), Gulf of Mexico.

External morphology. Columnar to ficiform sponges, that can possess lateral protuberances or branches ( Fig. 1View FIGURE 1). Small, 20–30 mm tall and 10–20 mm thick, attached to the substrate by the entire base. Surface is smooth, with marked water canals on the surface of the choanosomal skeleton. Oscules or pores are not visible to the naked eye. Color is beige to whitish in ethanol and when dry.

Skeleton. The ectosome is composed by a layer of overlapped phyllotriaenes ( Figs. 2View FIGURE 2 A–B), numerous acanthomicroxeas and acanthorhabds, and some amphiasters. Pores are surrounded by these microscleres. The choanosome has regular trider-type desmas with smooth and/or tuberculated tubercles; the sculpture of the tubercles is related to the stage of formation of the desma: smooth tubercles in earlier stages and tuberculated when older; the extremities of the desmas also varies, spine-like and smooth when young, or with a tubercle on the top when older ( Figs. 2View FIGURE 2 C–H, Fig. 3View FIGURE 3). Subtylostyles to tylotes are transverse to the surface, and cross both parts of the skeleton. Acanthorhabds and acanthomicroxeas are very abundant and spread through the entire skeleton; amphiasters are few and dispersed.

In addition, we have found some spicules with a strange appearance in the lower part of the sponge in the paratype DOP1976 ( Fig. 3DView FIGURE 3). They resemble irregular disco- to phyllotriaenes with a strong sculpture that have been developed in the lower part and merged with the desma skeleton. This skeleton formation, previously observed in other lithistid demosponges, may have the purpose of consolidating the basal skeleton of the sponge.