Rhynchozoon itaparicaensis, Almeida & Souza & Farias & Alves & Vieira, 2018

Almeida, Ana C. S., Souza, Facelucia B. C., Farias, Jamile, Alves, Orane F. S. & Vieira, Leandro M., 2018, Bryozoa on disarticulated bivalve shells from Todos os Santos Bay, northeastern Brazil, with the description of two new species, Zootaxa 4434 (3), pp. 401-428: 420-423

publication ID

https://doi.org/10.11646/zootaxa.4434.3.1

publication LSID

lsid:zoobank.org:pub:4E6E9F71-801E-4657-91DA-51F0B06807F6

persistent identifier

http://treatment.plazi.org/id/03E087AD-FFD6-9204-13ED-192BFDBB3AC0

treatment provided by

Plazi

scientific name

Rhynchozoon itaparicaensis
status

n. sp.

Rhynchozoon itaparicaensis   n. sp.

( Figs 10A –F View FIGURE 10 , 11A –D View FIGURE 11 ; Table 12)

Rhynchozoon verruculatum   : CANU & BASSLER, 1928: P. 31, PL. 7, fIgS 2, 3.

Rhynchozoon verruculatum   : VIEIRA et al., 2008: P. 33 (IN PART).

Rhynchozoon verruculatum   : ALMEIDA et al., 2015A: P. 5 (IN PART).

NOT Cellepora verruculata   : SMITT, 1873: P. 50, PL. 8, fIgS 170–172.

Material examined. Holotype: UFBA 1629, on valves of Pinctada imbricata     . Paratypes: UFBA 1635, UFBA 1638, on valves of Pinctada imbricata   , USNM 8564, Rhynchozoon verruculatum   , F. Canu & R. Bassler det., Costa dos Coqueiros, Arembepe, Bahia, Brazil, coll. 1877 by Steamer Norseman.  

Type locality. Itaparica Beach, Todos os Santos Bay, Bahia State, NE Brazil.

Etymology. Alluding to the type locality, Itaparica.

Description. Colony encrusting, uni- to multilaminar. Zooids ovoid at growing edge ( Fig. 10A View FIGURE 10 ), separated by low ridges, with 18–20 marginal pores. Autozooids ( Figs 10B View FIGURE 10 , 11A View FIGURE 11 ) strongly calcified, delimited by slightly raised lateral walls; frontal wall rugose, with small, rounded, scattered nodules, imperforate except for a single row of 12– 16 large, marginal pores. Primary orifice ( Figs 10C View FIGURE 10 , 11B View FIGURE 11 ) small relative to frontal shield length; broader than long, with 14–18 rounded denticles laterally and distally around margin; proximal edge with distinct, shallow, U-shaped median sinus; condyles small and triangular at proximal orificial corners. No oral spines. Primary orifice often obscured in peristome due to secondary calcification. Large suboral avicularium ( Figs 10D View FIGURE 10 , 11C View FIGURE 11 ) with well- developed chamber proximolateral to orifice on one side, with single cylindrical tubercle on opposite side, separated by U-shaped, laterally offset pseudosinus in secondary orifice; autozooids without large suboral avicularium may develop deep peristome with 3–4 rounded tubercles ( often only 2 are distinct), obscuring primary orifice. Suboral avicularium with hooked rostrum, elongate-triangular mandible with curved edge, somewhat scimitar-like, with short uncinate process projecting into orifice. Frontal avicularia ( Fig. 10A, E View FIGURE 10 arrow) numerous, up to 4 per zooid ( frequently 2), usually located at zooidal margin and directed distolaterally; rostrum diamond shaped, but sometimes with rounded proximal end; small to moderate in size, with complete crossbar. Ovicell ( Figs 10F View FIGURE 10 , 11D View FIGURE 11 ) hyperstomial, immersed with increasing calcification; ooecia subglobular and frontally flat, wider than long; ectooecium frontally uncalcified, leaving nearly semicircular tabula of exposed entooecium, with narrow labellum along proximal margin.

Remarks. Among Rhynchozoon   species that have the primary orifice with a distinct, shallow, U-shaped median sinus, no oral spines, and large suboral avicularium, Rhynchozoon itaparicaensis   n. sp. most closely resembles Rhynchozoon scimitar   Dick & Grischenko, 2016, due the distinct scimitar-like shape of the suboral avicularium. Differences between R. itaparicaensis   n. sp. and R. scimitar   include the suboral sinus ( deeper and narrower in R. scimitar   ); the shape of the condyles ( triangular in R. itaparicaensis   n. sp. but rounded in R. scimitar   ), the position of the suboral avicularium ( immersed in the secondary orifice and with a short uncinate process in R. itaparicaensis   n. sp.; at the secondary orificial margin and without uncinate process in R. scimitar   ); and the frequency of avicularia ( zooids typically have a suboral avicularium and two frontal avicularia in R. itaparicaensis   n. sp.; zooids have only one avicularium in R. scimitar   , never a suboral and frontal at the same time).

Other Rhynchozoon   species with the primary orifice and avicularia similar to those in R. itaparicaensis   n. sp. are Rynchozoon documentum   Hayward & Cook, 1983; Rhynchozoon fistulosum   Hayward, 1993; Rhynchozoon ryukyuense   Dick & Grischenko, 2016; and Rhynchozoon solitarium   Tilbrook, 2006. However, whereas R. itaparicaensis   n. sp. has a single suboral avicularium, scimitar-like, the suboral avicularium of R. documentum   is subtriangular; R. fistulosum   has two suboral avicularia; the suboral avicularium of R. ryukyuense   varies from small and triangular to large and rectangular and that of R. solitarium   is asymmetrically spatulate.

Canu & Bassler (1928) identified specimens from Bahia as Rhynchozoon verruculatum   , however, it truly belong to R. itaparicaensis   n. sp. ( Fig. 11A –D View FIGURE 11 ). These two species differ in the number of oral tubercles (up to 4, but commonly 2, in Rhynchozoon itaparicaensis   n. sp., 4–6 in R. verruculatum   ); the shape of the suboral avicularium (scimitar-like in R. itaparicaensis   n. sp., diamond-shaped in R. verruculatum   ); and the number and shape of the frontal avicularia (up to 4, varying from drop-shaped to diamond-shaped in R. itaparicaensis   n. sp., single and diamond-shaped in R. verruculatum   ).

Rhynchozoon itaparicaensis   n. sp. is a common shallow water species at Bahia, frequently found on hard substrata such as shells and calcareous nodules ( Canu & Bassler 1928).

Distribution. Atlantic: Brazil ( Bahia).

CANU

University of Canterbury

NOT

Nottingham City Natural History Museum

Bay

Mus�um d'Histoire Naturelle de Bayonne

for

Forssa Museum of Natural History

due

University of Dundee

may

Adygean State University

per

City Museum

such

Sukhumi Botanical Garden of Georgian Academy of Sciences

Canu

University of Canterbury

Kingdom

Animalia

Phylum

Bryozoa

Class

Gymnolaemata

Order

Cheilostomatida

Family

Phidoloporidae

Genus

Rhynchozoon

Loc

Rhynchozoon itaparicaensis

Almeida, Ana C. S., Souza, Facelucia B. C., Farias, Jamile, Alves, Orane F. S. & Vieira, Leandro M. 2018
2018
Loc

R. itaparicaensis

Almeida & Souza & Farias & Alves & Vieira 2018
2018
Loc

R. itaparicaensis

Almeida & Souza & Farias & Alves & Vieira 2018
2018
Loc

Rhynchozoon itaparicaensis

Almeida & Souza & Farias & Alves & Vieira 2018
2018
Loc

Rhynchozoon itaparicaensis

Almeida & Souza & Farias & Alves & Vieira 2018
2018
Loc

R. itaparicaensis

Almeida & Souza & Farias & Alves & Vieira 2018
2018
Loc

Rhynchozoon itaparicaensis

Almeida & Souza & Farias & Alves & Vieira 2018
2018
Loc

R. itaparicaensis

Almeida & Souza & Farias & Alves & Vieira 2018
2018
Loc

R. itaparicaensis

Almeida & Souza & Farias & Alves & Vieira 2018
2018
Loc

Rhynchozoon ryukyuense

Dick & Grischenko 2016
2016
Loc

R. ryukyuense

Dick & Grischenko 2016
2016
Loc

Rhynchozoon solitarium

Tilbrook 2006
2006
Loc

R. solitarium

Tilbrook 2006
2006
Loc

Rhynchozoon fistulosum

Hayward 1993
1993
Loc

R. fistulosum

Hayward 1993
1993
Loc

documentum

Hayward & Cook 1983
1983
Loc

R. documentum

Hayward & Cook 1983
1983