A Reexamination of Some Species of Ampelisca (Crustacea: Amphipoda) From the East Coast of North America

Abstract

Ampelisca verrilli n. sp. occurs from the intertidal to 50 m from southern Cape Cod to at least North Carolina. Individuals from North Carolina are small and slightly divergent in morphology from those from Massachusetts. A. macrocephala Liljeborg, with which A. verrilli has been confused for many years in New England, is figured. It occurs from just south of Cape Cod north, and from Nova Scotia north overlaps the range of A. eschrichti Krøyer. A. agassizi (Judd) (formerly known as A. compressa) is redescribed. Its range in the east is from Nova Scotia to the Caribbean at shallow inshore depths to 450 m. Eastern populations are closely similar to those from the eastern Pacific. A. declivitatis n. sp., which has been confused with A. spinimana Chevreux, is known from west of Greenland to the middle Atlantic States at lower continental shelf to bathyal depths, overlapping the range of A. agassizi on the continental shelf and the ranges of deep-sea species well down the continental slope. Parasitic worms, probably neorhabdocoele Turbellaria, occur in A. declivitatis. The incidence of intersexuality is high, but it does not appear to be related to parasitism by Turbellaria and may result from a polygenic-hormonal sex determination mechanism. A key is provided to the 24 species of Ampelisca known or suspected from eastern North America.

Dense ampeliscid bed on the Canadian Beaufort Shelf: an explanation for species patterns

“…These Arctic ampeliscids have high caloric value for gray whale predators (Highsmith and Coyle 1990;Tu et al 2015;Demchenko et al 2016) and along with ~ 150 other prey species provide ~ 220,800 kg of food per gray whale during the gray whales' ~ 184 day residence in the Arctic (Jones and Swartz 2009). Ampeliscids are also a resource for demersal fish, nemerteans, polychaetes and sea stars, and also their associated parasites (Mills 1967;Franz and Worley 1982;McDermott and Snyder 1988;Franz and Tanacredi 1992;Sheader 1998;Cui et al 2012). Surface feeding seabirds consume ampeliscids when they are brought to the surface by benthic feeding gray whales (Grebmeier and Harrison 1992) and pelagic fish prey on ampeliscids migrating into the water column to disperse or mate (Borowsky and Aitken-Ander 1991;Sudo and Azeta 1992;Dauvin and Zouhiri 1996).…”

Amphipods of the Family Ampeliscidae (Gammaridea). IV. Infraspecific Variation in Ampelisca agassizi

“…Reid (1951:197) stated "there appears to be a great range of real minor variations which is very strange considering the great constancy of characteristics in many species in other genera." However, Barnard (1960:6) Barnard (1960) Figure 1K) and not the transversely rounded form figured by Mills (1967: Figure 3J) and Bousfield (1973:Figure 38 Figure 1. Ampelisca agassizi; A. from Dickinson (1982): British Colombia; B. from Barnard (1954a): California;C. from Barnard (1954a): California; D. from Barnard (1954b): Caribbean; E. from Barnard (1954b) …”

“…In the western Atlantic this species is recorded from southern Nova Scotia to the Caribbean Sea in depths to 450 m (Barnard 1954b, Mills 1967, Bousfield 1973. Population densities of 15,000/m2 have been reported by Dickinson et al (1980) in the Middle Atlantic Bight region.…”

Ampeliscidae (Crustacea, Amphipoda) from the IceAGE expeditions

“…This is mainly due to the extensive combined works from Drs Dauvin, Bellan-Santini and Kaïm-Malka over many years. Whilst these researchers have focused on northern Atlantic waters (along with authors such as Sars 1895, Mills 1967, 1971), there has also been work on various parts of the Pacific Ocean. These include extensive studies on the eastern and Northern Pacific (Barnard 1954, 1961, and 1967, Dickinson 1982, 1983), and the western and tropical Pacific (Gurjanova 1951, 1955, Ren 2006, Dang and Le 2013).…”