Association between Hyperoche martinezii (Amphipoda: Hyperiidae) and ctenophores from the Buenos Aires coast, Argentina (South-western Atlantic Ocean)

ABSTRACT

This survey examined the association between the hyperiid amphipod Hyperoche martinezii and ctenophores off the Argentinian coast (38°08′17″S, 57°31′18″W) through the evaluation of seasonality, prevalence and intensity of infection during an annual cycle. Medusae were also examined but only the ctenophores Mnemiopsis leidyi, Pleurobrachia pileus and Beroe ovata showed this association during the austral mid-spring to mid-summer. A total of 502 hyperiids were obtained; most (422 individuals) were larval stages, 53 juveniles and 27 adults. Mnemiopsis leidyi had the highest number of hyperiids with 98.6%, followed by P. pileus (0.80%), and B. ovata (0.60%). Total prevalence was 2.0 and intensity of infection ranged between 1 and 17 hyperiids per ctenophore. The host with highest prevalence was B. ovata (4.54), followed by M. leidyi (3.76) and P. pileus (0.1). Prevalence values had some correlations with the increase in the total length of B. ovata (r = 0.480, P = 0.006) and M. leidyi (r = 0.501, P < 0.001), and between total length and intensity in B. ovata (r = 0.425, P = 0.017). The hyperiid was found in different parts of the host body: larval stages were found in the canal close to the subtentacular comb row and the stomodeum, whereas juvenile/adult stages were observed with a resting posture on the external surface of the ctenophores. The known geographic distribution of H. martinezii was extended; this finding represents the addition of three new hosts for this hyperiid.

RESPONSIBLE EDITOR:

• David Thieltges

KEYWORDS:

• Biological interaction
• ctenophores
• gelatinous zooplankton
• Hyperiidae
• Mar del Plata Harbour

Acknowledgements

The authors thank Dr Claudia Bremec and Steven Ryan Gray for their help with the English grammar and style of this manuscript. We thank the anonymous reviewers for their comments, which greatly improved this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCiD

Francisco Alejandro Puente Tapia http://orcid.org/0000-0002-5815-2600

Additional information

Funding

This work was supported by the Consejo Nacional de Investigaciones Científicas y Técnicas under grants PIP 2012-0152 and PIP 2013-00615; Universidad Nacional de Mar del Plata under grant EXA 734/15; and Agencia Nacional de Promoción Científica y Tecnológica under grant PICT 2013-1773. This is INIDEP contribution no. 2000.