Reteporella victori, Ramalho & López-Fé & Rueda, 2018

Ramalho, Laís V., López-Fé, Carlos M. & Rueda, José Luis, 2018, Three species of Reteporella (Bryozoa: Cheilostomata) in a diapiric and mud volcano field of the Gulf of Cádiz, with the description of Reteporella victori n. sp, Zootaxa 4375 (1), pp. 90-104 : 98-100

Reteporella victori n. sp.

( Fig. 5A–G ; Table 3)

Material examined. Holotype: MNCN 25.03/3996, Station DA-07, Gazul MV, 24 June 2010, benthic dredge, 491–495 m depth, R/V Emma Bardán, Indemares-Chica 0610, IEO coll.

Material used for SEM. MNCN 25.03/4001, Station DA-07, Gazul MV, 24 June 2010, benthic dredge, 491– 495 m depth, R/V Emma Bardán, Indemares-Chica 0610, IEO coll.

Diagnosis. Frontal surface of the colony very rugose, owing to projecting zooidal peristomes. Autozooids tubular, elongate, smooth frontally, with scarce, small areolar pores; peristome long and raised, with a long median fissure, fused along most of its length, and a drop-shaped pseudospiramen; two, circular to oval, peristomial avicularia with serrate rostrum and placed on a short cystid; triangular avicularia located on the frontal shield, with trifoliate palatal foramen. Dorsal side with raised sutures, pores and two types of avicularia (circular to oval and triangular) located inside the fenestrulae and on the surface.

Description. Colony fragment large, 1 cm long by 1.6 cm wide, with oval fenestrulae ( Fig. 5A, G ). Autozooids tubular, elongate, longer than wide, opening on the frontal surface in alternate series of 4–5 zooids. Frontal surface smooth, with scarce (5–9), small areolar pores ( Fig. 5B–C ). Peristome raised, sometimes with a laminar projection on one side, hiding the primary orifice. Primary orifice almost circular, distal edge usually beaded, occasionally smooth owing to a well-developed outer rim, with a pair of large condyles at the proximal corners and proximally with a highly variable developed lyrula ( Fig. 5C–D ). Spines not observed. A long fissure (195–244, mean 217, µm long), fused along almost its entire length, ends in a drop-shaped pseudospiramen ( Fig. 5C ). A pair of lateral avicularia (rarely one or three) placed on the edge of the peristome, on each side of the labial fissure, rarely on the frontal shield, proximolaterally directed, raised off the surface by a short cystid; rostrum rounded, serrated, mandible D-shaped, columella small; crossbar complete ( Fig. 5C, E ). Avicularium located on the frontal shield, triangular, palate with trifoliate foramen, a small columella and complete crossbar ( Fig. 5C, F ). Ooecium longer than wide, widened distally, depressed proximally, depression hidden by the peristomial labellum; a long, median fissure crossing the whole length and ending above the labellum ( Fig. 5B–C ). Dorsal side with raised sutures and pores; both types of avicularia (circular and triangular) seen on the frontal surface present dorsally, mainly located inside the fenestrulae, but also on the surface ( Fig. 5G ).

Etymology. Named after Dr. Victor Díaz del Rio, one of the first researchers to discover MVs in the Gulf of Cádiz, and responsible of the Indemares-Chica project that made possible to collect a large part of the material used in this study.

Remarks. The new species can be distinguished from R. mediterranea and R. pelecanus mainly by the presence of circular, peristomial avicularia with a serrated rostrum, raised by a short cystid. In addition, R. victori n. sp. has a long median fissure partially fused, forming a drop-shaped pseudospiramen. A further diagnostic feature of R. victori n. sp. is the frontal avicularium with a trifoliate, palatal foramen. The widespread Mediterranean Reteporella couchii ( Hincks, 1878) , similar to R. victori n. sp. in the colony and zooid shape, has 2– 4 delicate, distal oral spines absent in R. victori n. sp., a single laterooral avicularium, placed on a very elongate cystid (0.3 mm long), projecting conspicuously from the colony surface, and a sporadic large frontal avicularium (200 µm long), proximally directed, with an elongate, paralled-sided rostrum, rounded distally. Reteporella incognita Hayward & Ryland, 1996 , from Ireland, has a large mid-proximal foramen, a single, large (80 µm long), laterooral avicularium, placed on a cystid variable in length (0.15–0.3 mm long), frontal avicularium large (80–130 µm long), and the ooecium as broad as long, lacking a labellum and with the frontal longitudinal fissure extending for most of its length ( Hayward & Ryland 1996).

The trifoliate palatal foramen is present in two species of the Atlanto-Mediterranean region, Reteporella feuerbonii Hass, 1948 and Sertella gracilis Jullien & Calvet, 1903 . Reteporella feuerbonii from the Mediterranean differs from R. victori n. sp. in having one or two pseudosinuses at one or both sides of the peristomial avicularium, suboral avicularium with smooth rostrum and ooecia with a long fissure overpassing the proximal border. Sertella gracilis Jullien & Calvet, 1903 , found near the Island of Pico (Açores) and not further recorded since its first description, differs from R. victori n. sp. in having 4–6 spines and a lower peristome with a much shorter suture and, consequently, a pseudospiramen much closer to the edge of the peristome. High-quality SEM images of the syntypes of this species are accessible online at the website of the Muséum National d’Histoire Naturelle de Paris (https://science.mnhn.fr/institution/mnhn/collection/ib/item/2008-3729?listIndex=4&listCount=27&lang=en_ US). Sertella gracilis is a well-defined species belonging to the genus Reteporella , but this results in a homonymy with the southern Pacific Reteporella gracilis Gordon, 1989 , whose resolution is out of the aim of this work.

Distribution. Gulf of Cádiz (only at Gazul MV) (present study). The colonies were collected at the base of Gazul MV on massive authigenic carbonates (mainly slabs) colonized by small sponges ( Haliclona ), serpulid polychaetes ( Filograna ), hydrozoans ( Polyplumaria ), and echinoids ( Cidaris cidaris, Gracilechinus acutus).

Figures

FIGURE5. Reteporella victori n. sp. MNCN 25.03/4001.A, general view of the colony fragment; B, general view of a part of the colony showing frontal surface and fenestrulae; C, detail of a branch with fertile and infertile zooids. Note the ong fissure ending in a pseudospiramen; D, close-up of the primary orifice with beaded anter; E, close-up of an oval avicularium with serrated rostrum and small columella on a short cystid; F, triangular avicularium with a trifoliate palate and slightly raised rostrum; G, dorsal side with fenestrulae, sutures and avicularia. Scale bars: A, 4 mm; B, 500 µm; C, 200 µm; D, 100 µm; E–F, 25 µm, G, 300 µm.