Document of bibliographic reference 348348

BibliographicReference record

Type

Bibliographic resource

Type of document

Journal article

BibLvlCode

AS

Title

Brooding comatulids from the southwestern Atlantic, Argentina (Echinodermata: Crinoidea)

Abstract

Isometra vivipara and Phrixometra nutrix are two brooding feather stars (order Comatulida) that are widely distributed along the southern tip of South America to the Antarctic. We examined 210 specimens of I. vivipara and 38 specimens of P. nutrix collected during five cruises in the southwestern Atlantic between 91 and 642 m depth. Specimens were analyzed and deposited in the National Invertebrate collection, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. Isometra vivipara reaches an arm length of 49 mm long and shows two stages of brooding: in the female genital pinnules and on the cirri of the mother. In this paper, we propose that spermatozoa reach the ovary via the ambulacral groove. By contrast, P. nutrix is smaller with a maximum recorded size of 26.8 mm, and brooding occurs only inside the female genital pinnules. Here, we record, for the first time for P. nutrix, spermatozoa shape and a cleaved egg attached externally to a genital pinnule of a female. The distributions of both species and their abundances in some areas could be related to their doliolaria larval stage. In addition, we extend the bathymetric range of P. nutrix to 512 m in Marine Protected Area Namuncurá/Burdwood Bank and distribution to the Mar del Plata Submarine Canyon area. We also propose mode of reproduction and developmental patterns as attributes for identification and possible explanations for their differences in distribution.

WebOfScience code

https://www.webofscience.com/wos/woscc/full-record/WOS:000692154100001

Bibliographic citation

Pertossi, R.M.; Penchazadeh, P.E.; Martinez, M.I. (2021). Brooding comatulids from the southwestern Atlantic, Argentina (Echinodermata: Crinoidea). Mar. Biodiv. 51: 59. https://dx.doi.org/10.1007/s12526-021-01194-9

Topic

Marine

Is peer reviewed

true