A review of Gammaridae (Crustacea: Amphipoda): the family extent, its evolutionary history, and taxonomic redefinition of genera

Abstract

By molecular analysis of a high number of gammarids, including 29 out‐group genera, we could assure the monophyly of Gammaridae. To avoid the paraphyly of the family, we propose the omission of Pontogammaridae, Typhlogammaridae, and all Baikalian families. Similarly, the genera Fontogammarus, Sinogammarus, Lagunogammarus, Pephredo, Neogammarus, and Laurogammarus may be cancelled. But, tens of Baikal genera, nested within Gammarus, are so diverse that they must be retained, although rendering Gammarus paraphyletic. Besides we propose the polyphyletic Echinogammarus–Chaetogammarus group to be divided into monophyletic genera Echinogammarus s. str., Homoeogammarus, Parhomoeogammarus, Marinogammarus, Relictogammarus gen. nov., Chaetogammarus, and Trichogammarus gen. nov. These solutions made it possible to complete the first analysis of the family evolution in light of its phylogeny. Perimarine clades are mainly basally split clades, whereas in some ancient lakes extremely rich endemic faunas had developed polyphyletically. The troglobiotic Typhlogammarus group from Dinarides and Caucasus formed a monophylum, whereas the troglobiotic assemblage of Gammarus species is highly polyphyletic. Reduction of the uropod III endopodite, which classically distinguishes between the genera Gammarus and Echinogammarus, appeared to be highly polyphyletic. Protective dorsal pleonal projections occur scattered across the family and beyond, whereas lateral projections were limited to species of ancient lakes, so both structures were polyphyletic. The evolutionary history of Gammaridae was investigated with ten different calibration schemes, which produced incompatible results; however, the most probable scenario is a late rise of the family, which can only explain the absence of Gammaridae species around the Indo‐Pacific. © 2015 The Linnean Society of London

The complete mitochondrial genome of Gammarus roeselii (Crustacea, Amphipoda): insights into mitogenome plasticity and evolution

“…At a higher taxonomical level, the families included in our study are targets of molecular phylogenetic reassessments (Hou & Sket, 2016;Romanova et al, 2016a). Our results, along with Macher et al (2017a), clearly support the conclusion that Gammaridae is not a monophyletic family.…”

“…However, the genus Gammarus does not appear to be monophyletic in the present study, as the three other Gammarus species G. lacustris, G. cheuvreuxi and G. duebeni are more closely related to Baikalian families. However, the phylogenetic status of Gammarus fluctuated over the recent years, sometimes being considered monophyletic (Hou et al, 2011), monophyletic but with low support (Macher et al, 2017a) or paraphyletic (Hou & Sket, 2016). These discrepancies might be caused by incomplete taxon sampling and/or limited informative content of used markers.…”

“…Specifically, 18 species represent the ingroup, including seven species from the Gammaridae family and 11 species belonging to five families proposed by Hou & Sket (2016), based on partial COI sequences and three nuclear genes, to represent a broader definition of Gammaridae, i.e., Gammarridae sensu lato. Two additional species, Parhyale hawaiiensis and Pseudoniphargus sorbasiensis, were used as an outgroup to root the resulting tree (Romanova et al, 2016a;Macher et al, 2017a) (Table 1).…”

Amphipoda (Crustacea: Malacostraca) fauna of the inland-waters of Gökçeada Island

“…Kuzey Amerika'nın güneybatısı hariç neredeyse Holarktik bölgenin her yerinde, kaynaklar, dereler, akarsular, göller, kıyısal göller ve denizel littoral zonda dağılım gösterirler (Hou and Sket, 2015). Gammaridae familyasının tür sayısı bakımından en zengin cinslerinden biri olan Gammarus cinsine ait olan türlerin çoğu yüzey sularında yaşarken, birkaçı kuyular, mağaralar ve diğer yeraltı habitatlarından rapor edilmiştir (Karaman and Pinkster, 1977).…”

A new species of freshwater Chaetonotidae (Gastrotricha, Chaetonotida) from Obodska Cave (Montenegro) based on morphological and molecular characters

“…A few endemic species of invertebrates are known from this cave, e.g., Amphipoda: Metohija carinata Absolon, 1927; Gastropoda: Plagigeyeria montenigrina Bole, 1961 and Coleoptera: Adriaphaenops stirni Pretner, 1959. They occur only there or in a few other caves on the Adriatic coast (Pretner 1972;Pešić 2010;Hou & Sket 2015).…”