Uroptychus tuerkayi sp. nov. (Anomura, Chirostylidae), a new squat lobster from the Atlantis-Great Meteor Seamount Chain in the eastern Atlantic

Crustaceana ◽  
2017 ◽  
Vol 90 (7-10) ◽  
pp. 807-817
Author(s):  
Keiji Baba ◽  
Enrique Macpherson

A new species of chirostylid squat lobster,Uroptychus tuerkayisp. nov., is described based upon material collected by the French “Seamount 2” project (1993) from the Atlantis-Great Meteor Seamount Chain south of the Azores Islands, at a depth of 340-730 m.Uroptychus tuerkayiresemblesU. maroccanusTürkay, 1976 from the Moroccan coast, but it can be readily distinguished by the eyes being distinctly longer instead of as long as broad (globular inU. maroccanus), the antennal article 5 with a small instead of prominent distomesial spine, the anterolateral spine of the carapace slightly smaller than or subequal to, instead of much smaller than the lateral orbital spine, the pterygostomian flap anteriorly acuminate and not strongly produced to a spine as inU. maroccanus, and in having pereopod 1 with obsolescent instead of distinct spines on the merus and carpus. This is the sixth species ofUroptychusfrom the eastern Atlantic. A key to the eastern Atlantic species ofUroptychusis provided.


Zootaxa ◽  
2021 ◽  
Vol 4966 (3) ◽  
pp. 349-358
Author(s):  
TOMOYUKI KOMAI

A new species of the chirostylid squat lobster genus Uroptychodes Baba, 2004, U. fuscilineatus, is described and illustrated on the basis of a single ovigerous female from the Uraga Channel, central Japan, at depth of 250 m. The new species appears most similar to U. spinimarginatus (Henderson, 1885) and U. yapensis Dong, Gan & Li, 2021 among the 13 known congeners, but is notable in the pereopod 2 not being definitely more slender than the pereopods 3 and 4 and the remarkably spinose pereopods 1–4. A possible association of the new species with crinoid is suggested. An updated identification key to species of Uroptychodes is presented. 


Zootaxa ◽  
2018 ◽  
Vol 4524 (1) ◽  
pp. 77 ◽  
Author(s):  
KEIJI BABA ◽  
SHANE T. AHYONG ◽  
KAREEN E. SCHNABEL

The chirostyloidean squat lobster genus Gastroptychus Caullery, 1896 is revised and is split into two genera: Gastroptychus sensu stricto (type species, Ptychogaster spinifer A. Milne-Edwards, 1880) and Sternostylus new genus (type species, Ptychogaster formosus Filhol, 1884). Gastroptychus sensu stricto, is restricted to nine species with a sternal plastron, at sternite 3, abruptly demarcated from the preceding sternites (excavated sternum) by a distinct step forming a well-defined transverse or concave anterior margin at the articulation with maxillipeds 3, the maxillipeds 3 widely separated, with the distal parts accommodated in the excavated sternum between the left and right maxillipeds 3 when folded, and the P2–4 dactyli with the terminal spine demarcated by a suture. Sternostylus new genus, represented by 12 species, has the sternite 3 anteriorly bluntly produced medially and steeply sloping anterodorsally to the anterior sternite, with a pair of spines directly behind the anterior margin, the left and right maxillipeds 3 adjacent, and the P2–4 dactyli ending in an indistinctly demarcated corneous spine. The above-mentioned characters of Gastroptychus are consistent with Chirostylidae sensu stricto. Published molecular phylogenies indicate, however, that Sternostylus is the sister group to all the other Chirostylidae, and is designated the type genus of a new family, Sternostylidae. 


Ocean Science ◽  
2005 ◽  
Vol 1 (1) ◽  
pp. 17-28 ◽  
Author(s):  
H. van Haren ◽  
R. Groenewegen ◽  
M. Laan ◽  
B. Koster

Abstract. A high sampling rate (1 Hz) thermistor string has been built to accommodate the scientific need to accurately monitor high-frequency and vigorous internal wave and overturning processes in the ocean. The thermistors and their custom designed electronics can register temperature at an estimated precision of about 0.001° C with a response time faster than 0.25 s down to depths of 6000 m. With a quick in situ calibration using SBE 911 CTD an absolute accuracy of 0.005° C is obtained. The present string holds 128 sensors at 0.5 m intervals, which are all read-out within 0.5 s. When sampling at 1 Hz, the batteries and the memory capacity of the recorder allow for deployments of up to 2 weeks. In this paper, the instrument is described in some detail. Its performance is illustrated with examples from the first moored observations, which show Kelvin-Helmholtz overturning and very high-frequency (Doppler-shifted) internal waves besides occasionally large turbulent bores moving up the sloping side of Great Meteor Seamount, Canary Basin, North-Atlantic Ocean.


2021 ◽  
Vol 9 ◽  
Author(s):  
Jie Chen ◽  
Jianjun Zou ◽  
Aimei Zhu ◽  
Xuefa Shi ◽  
Dirk Nürnberg ◽  
...  

Investigating the composition and distribution of pelagic marine sediments is fundamental in the field of marine sedimentology. The spatial distributions of surface sediment are unclear due to limited investigation along the Emperor Seamount Chain of the North Pacific. In this study, a suite of sedimentological and geochemical proxies were analyzed, including the sediment grain size, organic carbon, CaCO3, major and rare earth elements of 50 surface sediment samples from the Emperor Seamount Chain, spanning from ∼33°N to ∼52°N. On the basis of sedimentary components, we divide them into three Zones (I, II, and III) spatially with distinct features. Sediments in Zone I (∼33°N–44°N) and Zone III (49.8°N–53°N) are dominated by clayey silt, and mainly consist of sand and silty sand in Zone II. The mean grain size of the sortable silt shows that the hydrodynamic condition in the study area is significantly stronger than that of the abyssal plain, especially at the water depth of 1,000–2,500 m. The CaCO3 contents in sediments above 4,000 m range from 20 to 84% but decrease sharply to less than 1.5% below 4,000 m, confirming that the water depth of 4,000 m is the carbonate compensation depth of the study area. Strong positive correlations between Al2O3 and Fe2O3, TiO2, MgO, and K2O (R > 0.9) in the bulk sediments indicate pronounced contributions of terrigenous materials from surrounding continent mass to the study area. Furthermore, the eolian dust makes contributions to the composition of bulk sediments as confirmed by rare earth elements. There is no significant correlation between grain size and major and minor elements, which indicates that the sedimentary grain size does not exert important effects on terrigenous components. There is significant negative δCe and positive δEu anomalies at all stations. The negative Ce anomaly mainly exists in carbonate-rich sediments, inheriting the signal of seawater. The positive Eu anomaly indicates widespread volcanism contributions to the study area from active volcanic islands arcs around the North Pacific. The relative contributions of terrestrial, volcanic, and biogenic materials vary with latitude and water depth in the study area.


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