Fangophilina submersa Schmidt, 1880

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 112-114

Fangophilina submersa Schmidt, 1880

Figures 69 a–h

Fangophilina submersa Schmidt, 1880: 73 , pl. X fig. 3; Topsent 1923: 2; Van Soest & Rützler 2002: 94, fig. 7A.

Material examined. RMNH Por. 9296, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station B23B, 7.297°N 55.3883°W, depth 99–101 m, rectangular dredge, 27 April 1966 (1 specimen) ; RMNH Por. 9309, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 51, 7.6833°N 57.0333°W, depth 98 m, bottom calcareous sand, 30 August 1970 (1 specimen) ; RMNH Por. 9365, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 59, 7.6333°N 56.95°W, depth 96 m, Van Veen grab, bottom sandy mud, shells, 24 August 1970 (1 specimen) ; RMNH Por. 9728, Suriname, ‘Luymes’ Guyana Shelf Expedition, station 2, 7.1667°N 53.6°W, depth 93 m, dredge, bottom sandy calcarenite, 24 August 1970 (1 specimen) ; RMNH Por. 9730, French Guyana, ‘Luymes’ Guyana Shelf Expedition, station 21, 6.05°N 53.2°W, depth 42 m, trawl, bottom sandy mud, 26 August 1970 (1 specimen) ; RMNH Por. 9732, French Guyana, ‘Luymes’ Guyana Shelf Expedition, station 16, 6.3°N 52.95°W, depth 56 m, trawl, bottom muddy calcareous sand, 26 August 1970 (1 specimen) ; RMNH Por. 9811, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station B23, 7.2976°N 55.3883°W, depth 99–101 m, Agassiz trawl, 27 April 1966 (2 specimens) ; RMNH Por. 9886, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station B23C, 7.2967°N 55.3883°W, depth 95 m, Van Veen grab, 27 April 1966 (1 specimen) ; RMNH Por. 10518, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 50, 7.7167°N 57.0833°W, depth 96 m, rectangular dredge, bottom sandy mud, 30 August 1970 (9 specimens) .

Description. Globular sponges ( Fig. 69 a), each with two prominent lateral strongly ‘hairy’ porocalices and a bushy spicular root, yellowish in alcohol, possibly orange in life (information on one of the labels). Between the porocalices and the root the surface is optically smooth, microhispid. Size on average 2–3 cm in diameter, porocalices approximately 1 cm in diameter, spicule palisade of porocalices may be up to 2 cm high. Porocalices differentiated into inhalant and exhalant functions (fide Topsent 1923, following Kirkpatrick 1902). Consistency somewhat compressible.

Skeleton. Strongly radiate, due to spicule tracts from the porocalices penetrating to the center of the sponge body. Long oxeas form the main spicules of the palisade surrounding the porocalices. Small prodiaenes form a special layer at the surface and on the bottom of the porocalices ( Topsent, 1923).

Spicules. ( Figs 69 b–h) Oxeas, plagiomono-, di- and triaenes, orthodi- and triaenes, anatriaenes, prodi- and triaenes, sigmaspires.

N.B. The diversity of the triaenes and the often broken condition of the rhabds made it virtually impossible to measure sufficient spicules to meet the minimum number of 15 spicules for each spicule type. For that reason I present here the ranges of the spicules only (excepting the sigmaspires which occurred in sufficient numbers).

Oxeas, sharply pointed, variable in length and exact measurements often problematic due to frequently broken, divisible in two size categories, (1) longer, ( Fig. 69 b), measured in the slides 2.8–10 mm x 24–50 µm, but there are also longer oxeas up to 25 mm, and (2) shorter ( Fig. 69 c) 780– 1800 x 12–21 µm.

Plagiotriaenes with characteristic oxhorn-shaped cladi, occurring in similar shaped monaene- ( Figs 69 d,d1), diaene- ( Fig. 69 d2) and triaene- ( Fig. 69 d3) conditions, rhabdomes 1800–2800 x 23–33 µm, cladomes of di- and triaenes 600–700 µm, cladi of mono-, di- and triaenes 360–450 x 24–31 µm.

Orthotriaenes ( Figs 69 e1), with diaene and triaene conditions, rhabdomes 1600– 2700 x 15–22 µm, cladomes 240–612 µm, cladi 125–380 µm.

Protriaenes, in diaene and triaene conditions, in three distinct categories, (1) robust ( Figs 69 f,f1) with thick cladi almost parallel arranged, rhabdomes 2600–400 x 18–32 µm, cladomes 110–144 µm, cladi 162–175 x 17–22 µm, (2) thinner ( Figs 69 f2,f2a), with very long thin more widely verging cladi, rhabdomes 2000–4800 x 10–13 µm, cladomes 140–200 µm, cladi 150–430 x 8–16 µm, and (3) thread-like, very thin ( Fig. 69 f3) with wispy to curly endings, usually in the diaene condition (only rarely triaenes), rhabdomes 960– 2300 x 2–4 µm, cladomes 16–20 µm, cladi 25–33 x 1–1.5 µm.

Anatriaenes ( Fig. 69 g), variable in size but not divisible in categories, rather sparsely present, rhabdomes 2400–3660 x 12–22 µm, cladomes 100–180 µm, cladi 72–125 x 11–20 µm.

Sigmaspires ( Figs 69 h,h1), spined all over, very variable in shape and length, the longer ones ( Fig. 69 h) characteristically double-curved, toxa-shaped, the smaller ( Fig. 69 h1) C- or S-shaped, 15– 23.2 –36 µm.

Distribution and ecology. Guyana Shelf, Florida (?), soft bottom, with 18 specimens in total, it is one of the more common species of the Guyana Shelf; depth occurrence 42–101 m (no depth known for the type material).

Remarks. The data on the specimens described here are closely similar in all details to Topsent’s (1923) redescription of (part of) the type from the Strassbourg Museum, ZMUS P0160, selected as lectotype by Van Soest & Rützler (2002) (p. 94). The same museum holds several dry fragments, ZMUS P0166, designated paralectotypes. There is also type material in the Berlin Museum, ZMB 6650 (slides) and in the Museum of Comparative Zoology, PORb-358. Schmidt’s material was of unknown Caribbean origin, but it is likely that it was from S or W of Florida, where the Agassiz material was collected. The present specimens are the first subsequent record of the species from the Western Atlantic.

Burton (1956, 1959) reported this species from respectively Zanzibar and West Africa, but these records very likely concern other species of Fangophilina . A slide of the West African record (Atlantide stat. 145) was examined, and this clearly differed in many aspects, such as the lack of plagiomonaenes, and thread-like prodiaenes, while anatriaenes were dominant and of clearly different shape from F. submersa . It is very likely that this slide represents F. kirkpatrickii Von Lendenfeld, 1907 . There are also a few dozen specimens from the Cape Verde Islands in the collections of Naturalis (CANCAP collections) labeled variously F. submersa and F. kirkpatrickii , which appear to conform to Von Lendenfeld’s description and differ from the Guyanan F. submersa .

Similarly, the Zanzibar record is likely to concern F. gilchristi Kirkpatrick, 1902 or F. hirsuta Von Lendenfeld, 1907 .

Figures

FIGURE 69. Fangophilina submersa Schmidt, 1880, a, habitus of one of nine specimens of RMNH Por. 10518 (scale bar = 1 cm), b – h, SEM images of spicules, b, longer oxea, c, shorter oxea, d – d 3, oxhorn plagiotriaenes, d, monoplagiotriaene, d 1, cladome of d, d 2, cladome of plagiodiaene, d 3, plagiotriaene, e, orthotriaene, e 1, cladome of e, f – f 3, protriaenes and modifications, f, robust prodiaene, f 1, cladome of robust protriaene, f 2, thinner protriaene, f 2 a, cladome of thinner prodiaene, f 3, threadlike thin prodiaene, g, cladome of anatriaene, h, double-curved long sigmaspire, h 1, single-curved short sigmaspire.