Two new deep-sea stalked barnacles, Arcoscalpellum epeeum sp. nov. and Gymnoscalpellum indopacificum sp. nov., from the Coral Sea, with descriptions of the penis in Gymnoscalpellum dwarf males

Abstract

The present study describes a new species of Arcoscalpellum Hoek, 1907, and a new species of Gymnoscalpellum Newman & Ross, 1971, collected by deep-sea expeditions led by the Muséum national d'Histoire naturelle (Paris) in the Coral Sea off New Caledonia, Papua New Guinea (PNG), the Solomon Islands and Vanuatu. Arcoscalpellum epeeum sp. nov. differs from all described species of Arcoscalpellum by the presence of a long, sharp, sword-shaped carina, which extends beyond the apices of the terga by 1/3 to 1/4 of their length. The species is dioecious, with large females and dwarf males that are sac-like, lack shell plates and are housed in paired receptacles at the inner edges of the scutal plates. Arcoscalpellum epeeum sp. nov. was collected in the waters of New Caledonia and Vanuatu. Gymnoscalpellum indopacificum sp. nov. differs from the six currently described species of Gymnoscalpellum by having a very small inframedian latus and a branched upper latus. The species is dioecious, with large females and dwarf males, the latter composed of 4 shell plates and housed in paired receptacles at the inner edges of the scutal plates. The penis of the dwarf males of G. indopacificum sp. nov. is about 0.8 of the total length of the male and has five side branches extending out along its length. Gymnoscalpellum indopacificum sp. nov. is distributed in the waters of Papua New Guinea, the Solomon Islands and Vanuatu, and represents the first record of this genus in the Indo-Pacific region.

Invertebrate diversity in the deep Great Australian Bight (200–5000 m)

“…Deep water barnacles have been relatively well documented in waters adjacent to Australia such as Antarctica (Newman & Ross, 1971), the Malay Archipelago (Hoek, 1883;Hoek, 1907;Hoek, 1913;Calman, 1919;Chan, 2009), New Caledonia Buckeridge, 1997;Jones, 2000;Chan et al, 2014) and New Zealand (Foster, 1978;Foster, 1980;Foster, 1981). The deep water barnacle fauna of Australia has been summarised by Jones (Jones, 2000;Jones, 2012;Jones, 1991) and Jones et al (Jones et al, 1990), but there are few recent taxonomic accounts that describe Australia's deep sea barnacles (e.g.…”

Structural specialties, curiosities, and record‐breaking features of crustacean reproduction

“…They are shorter lived than their carrying females or hermaphrodites, and thus, the females must repeatedly acquire new males during their lifetime (Høeg et al, ). It is largely unknown how these dwarf males fertilize the females but males of Verum brachiumcancri and Gymnoscalpellum indopacificum were shown to possess a long penis that reaches the mantle cavity of the female (Buhl‐Mortensen and Høeg, ; Chan et al, ).…”

First report on the complete mitochondrial genome of the deep-water scalpellid barnacle Arcoscalpellum epeeum (Cirripedia, Thoracica, Scalpellidae)

“…As of 24 August 2018, GenBank contains two complete mitochondrial genomes (mitogenomes) from hermaphrodite pollicipedid barnacles, but no mitogenomes from the other families. Scalpellids are one of the largest families of Scalpelliformes, with over 260 species and have either androdioecious or dioecious reproductive systems (Chan et al 2014). To understand the phylogenetic relationships and reproductive evolution of Scalpelliformes, we determined the first mitogenome of a deep-sea scalpellid barnacle, Arcoscalpellum epeeum, which is androdioecious.…”