Back to search
AnimaliaacceptedgenusAccepted
Orectopora

Orectopora

Grischenko, Gordon & Melnik, 2018

GBIF:148403743

0datasets
0year

0

Descendants

0

Children

0

Species

ABOUT

Descriptions(4)

Diagnosis. Colony erect, flabellate, subplanar, attached by short stalk. Surface gently frontally concave with distinct abfrontal surface, typically with short bilaterally compressed fascicles; essentially two-layered, comprising, in transverse section, initially contiguous, but then laterally diverging, autozooidal tubes, backed by discontinuous series of narrower kenozooidal tubes. Gonozooid not seen. Colony supported by semi-erect ancestrula and a few daughter zooids, strengthened by basal kenozooids and extrazooidal calcification; no boundary between protoecium and peristome.
Grischenko, Andrei V., Gordon, Dennis P., Melnik, Viacheslav P. (2018): Bryozoa (Cyclostomata and Ctenostomata) from polymetallic nodules in the Russian exploration area, Clarion - Clipperton Fracture Zone, eastern Pacific Ocean-taxon novelty and implications of mining. Zootaxa 4484 (1): 1-91, DOI: 10.11646/zootaxa.4484.1.1
Remarks. Orectopora n. gen. is exceptional among tubuliporines in having a bilaterally compressed colony in which zooidal apertures are confined to the distal margin in narrow subplanar fascicles backed by a discontinuous series of abfrontal kenozooidal chambers. Initial colony growth is reminiscent of that in Discantenna (Gordon & Taylor, 2010), having an inclined ancestrular peristome and initial colony growth supported by a basal abfrontal skirt of kenozooids. Subsequent colony growth seems very different, however, forming an elevated unilaminar disk of frontally opening zooids in Discantenna but a lobate fan of terminally opening zooids in Orectopora. Alternatively, the outer convex side of the lobate branches might be equivalent to the abfrontal surface of cyclostomes such as Nevianipora, such that the small zooids visible close to this face are the buds of autozooids (not kenozooids), which migrate towards the concave surface of the branches as they develop and become salient at the growing edge. This would explain the presence of some zooids of intermediate size that cannot be clearly identified as kenozooids or autozooids. If correct, this interpretation would likewise place Orectopora n. gen. close to Discantenna. In the absence of a gonozooid, the family attribution of Orectopora is uncertain.
Grischenko, Andrei V., Gordon, Dennis P., Melnik, Viacheslav P. (2018): Bryozoa (Cyclostomata and Ctenostomata) from polymetallic nodules in the Russian exploration area, Clarion - Clipperton Fracture Zone, eastern Pacific Ocean-taxon novelty and implications of mining. Zootaxa 4484 (1): 1-91, DOI: 10.11646/zootaxa.4484.1.1
Etymology. Latinized form of Greek orektos, stretched out, plus - pora, a common suffix for cyclostome bryozoans. Gender feminine.
Grischenko, Andrei V., Gordon, Dennis P., Melnik, Viacheslav P. (2018): Bryozoa (Cyclostomata and Ctenostomata) from polymetallic nodules in the Russian exploration area, Clarion - Clipperton Fracture Zone, eastern Pacific Ocean-taxon novelty and implications of mining. Zootaxa 4484 (1): 1-91, DOI: 10.11646/zootaxa.4484.1.1
Type species. Orectopora flabellum n. sp.
Grischenko, Andrei V., Gordon, Dennis P., Melnik, Viacheslav P. (2018): Bryozoa (Cyclostomata and Ctenostomata) from polymetallic nodules in the Russian exploration area, Clarion - Clipperton Fracture Zone, eastern Pacific Ocean-taxon novelty and implications of mining. Zootaxa 4484 (1): 1-91, DOI: 10.11646/zootaxa.4484.1.1

Export occurrence data

Darwin Core Archive (ZIP)

CLASSIFICATION

Taxonomic Classification Tree

AnimaliaBryozoaStenolaemataCyclostomataOrectopora

Occurrences with images

Source Information

Bryozoa (Cyclostomata and Ctenostomata) from polymetallic nodules in the Russian exploration area, Clarion - Clipperton Fracture Zone, eastern Pacific Ocean-taxon novelty and implications of mining

checklist

This dataset contains the digitized treatments in Plazi based on the original journal article Grischenko, Andrei V., Gordon, Dennis P., Melnik, Viacheslav P. (2018): Bryozoa (Cyclostomata and Ctenostomata) from polymetallic nodules in the Russian exploration area, Clarion - Clipperton Fracture Zone, eastern Pacific Ocean-taxon novelty and implications of mining. Zootaxa 4484 (1): 1-91, DOI: 10.11646/zootaxa.4484.1.1

Abstract

This work describes Bryozoa of the orders Cyclostomata and Ctenostomata found associated with polymetallic nodules collected by box-coring in the eastern part of the Russian exploration area of the Clarion-Clipperton Fracture Zone (CCFZ) under contract to Yuzhmorgeologiya. Scanning electron microscopic study of 358 cyclostome colonies and 14 ctenostome colonies from 4510–5280 m depth has resulted in the recognition of two new species of Ctenostomata, and 14 new species, nine new genera and two new families of Cyclostomata; three additional species of Cyclostomata are left in open nomenclature pending the discovery of missing reproductive characters. The taxonomic novelty is thus notable. One of the new Ctenostomata represents the first living example of the previously monotypic Late Cretaceous genus Pierrella. Twelve of the new cyclostome taxa have well-developed gonozooids, indicating that embryonic cloning (polyembryony) is normal in this deep-sea environment. On the other hand, one indeterminate tubuliporine and two rectangulates have dimorphic peristomes. In the latter two cases, enough mature colonies were found to suggest that this feature is normal, and that the dimorphic zooids are possibly female—in other words, capacious incubation chambers are apparently lacking, and therefore polyembryony would also be lacking or reduced. In one of these species, evidence is presented to suggest that the ancestrular zooid can reproduce precociously. Of the species reported here, only one has previously been found outside the exploration area, highlighting both the limited knowledge we have of bryozoans in the deep Pacific and/or a fauna that is largely endemic to the nodule environment. An additional 31 species of Cheilostomata have also been discovered that will be described in a subsequent publication. Most bryozoans are macrofaunal-sized, so are both inadequately determinable and overlooked in images obtained by remotely operated vehicles; yet, with 50 species, Bryozoa is the most speciose sessile macrofaunal phylum on the nodules. Nodules constitute hard substrata in an area otherwise mostly inhospitable for Bryozoa, hence mining would lead to loss of critical habitat. Further, as suspension-feeders, bryozoans are highly susceptible to smothering by suspended sediment, and non-mined areas closely adjacent to extraction zones would likely also be affected and their associated bryozoan fauna obliterated. More data are required on the distribution of the CCFZ bryozoan species elsewhere in the east Central Pacific to determine if mining would lead to local taxon extirpation or global extinction at both low and high taxonomic levels.

Grischenko A V, Gordon D P, Melnik V P, plazi (2018). Bryozoa (Cyclostomata and Ctenostomata) from polymetallic nodules in the Russian exploration area, Clarion - Clipperton Fracture Zone, eastern Pacific Ocean-taxon novelty and implications of mining. Plazi.org taxonomic treatments database. Checklist dataset https://doi.org/10.11646/zootaxa.4484.1.1 accessed via GBIF.org on 2026-06-14.

CC0Published 9/25/2018View dataset
GBIF Usage Key
148403743
Dataset Key
74b777c9-eae0-4770-8c86-dcbb10fb06b3
Origin
source
Backbone Key
10626115
Taxon ID
521587E4563C550909EEFD5E8E03F9CF.taxon
Last Crawled
6/10/2026
Last Interpreted
6/10/2026
View on GBIFSource Reference