Associations between gelatinous zooplankton and hyperiid amphipods (Crustacea: Peracarida) in the Gulf of California

Abstract

Hyperiid amphipods are pelagic crustaceans that live associated with gelatinous zooplankton including medusae, ctenophores, siphonophores, and salps. Standard plankton sampling disrupts natural associations, so the most reliable way to determine an association is through direct observation of the organisms in their environment. The planktonic fauna of the Gulf of California dwelling between 10 and 3000 m was surveyed using SCUBA diving and a remotely operated submersible (ROV) during March 2003. Here we report our observations on a total of 14 symbiotic associations found between the hyperiid amphipods and various taxa of gelatinous zooplankton. We found parental care behavior in a group of amphipods (Oxycephalidae) in which this phenomenon has not been previously reported. For two hyperiid species, Euthamneus rostratus and Vibilia australis, we present the first information on their symbiotic relations. Additional hosts were discovered for other well-known and widely distributed hyperiid species (i.e. Brachyscelus crusculum, Hyperoche medusarum). Photographic evidence of some of these interactions is included in this contribution. This is the first survey of these relationships in the Gulf of California, and many aspects of the ecology and biology of these symbioses remain to be studied.

The giant deep-sea octopus Haliphron atlanticus forages on gelatinous fauna

“…The fifth specimen included the remains of a salp chain along with the only crustacean found in the stomach contents (Fig S1d). This crustacean was identified as an amphipod of the genus Vibilia , which is known to specialize in parasitizing salps1920. This record corresponds with the amphipod gut-contents previously reported13, which may be indicative of ingestion as “by-catch” when the gelatinous host of the amphipods is consumed.…”

New records of hyperiids (Amphipoda, Hyperiidea) from surface waters of the central Mexican Pacific

“…Considering the new data, the known species richness of hyperiid amphipods from the central Mexican Pacific (80 species) is now comparable to that reported from adjacent tropical and subtropical areas, including the Gulf of California (Siegel-Causey, 1982: 106 species) and different areas of the Northwestern Tropical Atlantic, such as the Gulf of Mexico (Gasca, 2003(Gasca, , 2004LeCroy et al, 2009: 100 species) and the Sargasso Sea (Gasca, 2007: 89 species). Based on the revised list by Gasca (2009a), the number of species of hyperiids recorded in the entire Mexican Pacific has risen from 150 to 154.…”

“…The remaining four species, Primno evansi, Eupronoe laticarpa, Lycaea lilia, and Amphithyrus glaber have not previously been recorded in Mexican Pacific waters. In particular, L. lilia has never been recorded in Mexican waters (Atlantic + Pacific) before (Gasca, 2003(Gasca, , 2004(Gasca, , 2009aGasca & Franco-Gordo, 2008;LeCroy et al, 2009).…”

“…The Mexican Pacific has been divided into three main sectors, one with the potential influence of the California Current in the north, another with exclusively tropical waters in the south, and a transitional fringe in the central area in which both hydrographic conditions can occur seasonally (see Gasca, 2009a). The central and southern sectors of the Mexican Pacific are among the areas in which more efforts are needed to reveal the local hyperiid fauna; other sectors of the Eastern Pacific, such as the California area and Gulf of California have been surveyed (Siegel-Causey, 1982;Lavaniegos & Ohman, 1999;Gasca & Haddock, 2004;Gasca, 2005Gasca, , 2009a. A checklist of the hyperiid fauna of the Mexican Pacific, from the Baja California to the southern border of Mexico, was published recently by Gasca (2009a).…”

Sterile Surfaces of <i>Mnemiopsis leidyi</i> (Ctenophora) in Bacterial Suspension—A Key to Invasion Success?

“…Ctenophores bear a variety of invertebrate parasites. Amphipods of the suborder Hyperiidea (Crustacea: Amphipoda) are commonly found attached to the external epidermis [14] [15], while the metacercaria of three digenean trematode families (Trematoda: Digenea: Faustulidae, Lepocreadiidae, Hemiuridae) are commonly found embedded in the mesoglea, often concentrated in regions close to the subplate canals. Such parasites mature in fish predators of ctenophores and commonly occur with remarkable prevalence and infestation intensity [16].…”