![Thumbnail: [Volume 82, 1954-55 page 730]](/journals/rsnz/images/rsnz_82/thumbnails/rsnz_82_03_0845_0730_ac_02.gif)
Nephrops Leach, 1815.
norwegicus (Linn., 1758). Iceland; West Coast of Europe; Mediterranean.
japonicus Tapp.-Can., 1873. Japan.
thomsoni Sp. Bate, 1888. Philippine Islands; Formosa.
andamanicus W.-Mason, 1892. Andaman Sea; Bali Sea; South Africa.
reedi Carter, 1898. Eocene, London clay, England.
rubellus Moreira, 1903. Coast of Brazil; Atlantic South America.
arafurensis de Man, 1905. Kei Islands.
challengeri Balss, 1914. New Zealand waters.
sibogae de Man, 1916. Off Kei Islands.
sagamiensis Parisi, 1917. Japan.
costatus Rathbun, 1918. Pleistocene, Panama Canal Zone.
sp. Rathbun, 1918. Pleistocene, Panama Canal Zone.
maoensis Rathbun, 1920. Miocene, Dominican Republic.
aequus Rathbun, 1920. Miocene, Dominican Republic.
intermedius Balss, 1921. Japan.
binghami Boone, 1927. Off British Honduras.
shastensis Rathbun, 1929. Cretaceous, California.
americanus Rathbun, 1935 Cretaceous, Texas.
norwegicus meridionalis Zar.-Cenarro, 1935. Spain.
Of the 19 species described, the fossil forms N. reedi, N. costatus, N. sp. Rathbun. N. maoensis, N. aequus, N. americanus and presumably N. shastensis can be separated out. These have all been described from fragments of fingers or palms only and are not well known All have large heavy fingers with prominent tubercles or carinae and sometimes bear spines.
N. norwegicus with its synonym N.n. meridionalis (see Holthuis, 1945) differs from all the other recent species in the following features; it has only five longitudinal carinae on the carapace posterior to the cervical groove, the dorsolateral margins of the rostrum are not continued on to the carapace as postrostral carinae, the antennal spine is small and the scaphocerite is narrow and lanceolate All other recent species have seven longitudinal carinae on the carapace posterior to the cervical groove, the dorsolateral margins of the rostrum continued on to the carapace as postrostral carinae, large prominent antennal spines and the scaphocerite broad and often circular in shape.
![Thumbnail: [Volume 82, 1954-55 page 731]](/journals/rsnz/images/rsnz_82/thumbnails/rsnz_82_03_0846_0731_ac_02.gif)
The Atlantic N. rubellus and N. binghami, from off Brazil and Honduras respectively, superficially resemble one another and can be distinguished from the Indopacific forms by the heavily spined chelipeds and the large number of spines on the carapace between the hepatic groove and the orbit.
The Indopacific species can be divided into three main groups (de Man, 1916). The first group has the carapace smooth or finely granulate, the terga of the 2nd to 5th abdominal somites conspicuously sculptured and prominent spinulose ridges on the chelae of the 1st pair of legs. To this group belongs N. japonicus, N. andamanicus, N. sagamiensis and N. intermedius, these last two being possibly synonymous. The second group also has the carapace smooth or finely granulate, but the terga of the 2nd to 5th abdominal somites appear almost smooth to the naked eye and there are no prominent ridges on the chelae of the first pair of legs. In this second group are the species N. thomsoni, N. challengeri and N. sibogae. The third group has the carapace distinctly spinulose and the abdominal somites conspicuously sculptured. This group contains the single species N. arafurensis.
The three closely allied species N. thomsoni, N. sibogae and N. challengeri can be distinguished readily by the fact that the two former have a dorsal longitudinal spinulose ridge on the cardiac region, while the latter has not. N. thomsoni has also a single, deep, transverse groove, broadly interrupted in the middle, on the terga of the 2nd to 5th abdominal somites, while N. sibogae has only an inconspicuous transverse row of shallow pits on these somites.
From the above it can be seen that there is in the New Zealand region a clearly distinguishable member of the widely distributed genus Nephrops. It is apparently closely related to two species, one of which occurs in East Indonesian waters and the other in Philippine waters. Our Nephrops has been found in 80 to 300 fathoms, in the Tasman Sea, off Cook Strait; off Manawarakau, Hawke Bay; off Tora, between Castlepoint and Cape Palliser, and off the Chatham Islands. It is probably widely distributed around our coasts in water of that depth, its striking colour and unmistakable form making it an easily recognisable species in our marine fauna.