Biodiversity Data Journal :
Single Taxon Treatment
|
Corresponding author: Wentao Niu (wentaoniu@tio.org.cn), Feng Zhang (zhangfeng@hbu.cn)
Academic editor: Bonnie Bain
Received: 22 Dec 2020 | Accepted: 07 Apr 2021 | Published: 08 Apr 2021
© 2021 Jianjia Wang, Dong Sun, Peng Tian, Dinyong Huang, Wentao Niu, Feng Zhang
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Wang J, Sun D, Tian P, Huang D, Niu W, Zhang F (2021) A small collection of Endeis juveniles (Arthropoda: Pycnogonida: Endeidae) sorted from the fouling organisms on the R/V Dayangyihao. Biodiversity Data Journal 9: e62343. https://doi.org/10.3897/BDJ.9.e62343
|
|
Endeis straughani Clark, 1970 was originally described from Queensland, Australia. Its range was extended to Ghana, West Africa when E. picta Bamber, 1979 was synonymised with E. straughani by
Five immature individuals gathered amongst hydroids during the 5th leg of the DY125-34 expedition were tentatively identified as E. straughani juveniles. Since these were collected from the fouling community on the ship’s hull, they probably originated in Port Louis (Mauritius) when the ship was docked there.
Indian Ocean, Mauritius, new record, fouling communities on ship hulls
The genus Endeis Philippi, 1843 includes 18 species distributed widely, except from the Arctic Ocean (
During the 5th leg of the DY125-34 expedition, which was returning to China from its work zone in the SWIR (Southwest Indian Ocean Ridge), five juvenile Endeis specimens were collected along with the hydroid, Leptothecata Cornelius, 1992 while sampling the water for zooplankton. Giving the difficulties associated with identifying juvenile specimens, this small collection (Fig.
Endeis straughani, (TIO2014DY34-5.003): A. trunk, dorsal view. (TIO2014DY34-5.002): B. trunk, ventral view. (TIO2014DY34-5.001): C. trunk, dorsal view; D. trunk, lateral view; E. leg 1; F. tarsus, propodus and claws of leg 1, enlarged, the arrow points to the obliquely short heel spine; G. tarsus, propodus and claws of leg 2, enlarged, the arrow points to the obliquely short heel spine. (TIO2014DY34-5.002): H. cephalon, ventral view, the arrow points to the oviger bud. Scale bars A and B = 1 mm; C, D and E = 0.5 mm; F, G and H= 0.2 mm.
During the 5th leg (from 5/7/2015 to 5/12/2015) of the DY125-34 expedition, on its return trip to China from the work zone in SWIR, the expedition continued to collect zooplankton samples. These samples were collected by pumping seawater through a pipe which had its intake located 3 m below the surface and the outlet of the pipe was wrapped in a 20 μm mesh net to ensure the minimum size of samples collected. Sampling occurred over a 12-hour period each day. At one point during the return trip, several juvenile specimens of Endeis were accidentally collected along with several hydroids.
The five pycnogonids (No. TIO2014DY34-5.001-005), along with the hydroids, were preserved in 90% ethanol and stored at the Third Institute of Oceanography, Ministry of Natural Resources, China. Photographs were taken with an Auto-montage system on a Leica M205 FA stereomicroscope and z-stacks were created with the LAS software (Version 3.8). Measurements of the pycnogonids were made axially, dorsally for the trunk, laterally for the proboscis and legs and are given in mm.
Phoxichilus charybdaeus (?).
Endeis straughani
Endeis picta
TIO2014DY34-5.001. Trunk glabrous, completely segmented. Collar with flat protuberances laterally. Cephalon with two short spines distally. Lateral processes separated by slightly more than their own diameter, each with 1-3 short distal dorsal spines. Ocular tubercle taller than its base diameter, with pointed peak; two pairs of eyes pigmented distinctly. Abdomen pointing slightly backwards, almost as high as ocular tubercle, with two lateral spines distally (Fig.
Proboscis barrel-shaped, leaning downwards at about 45 degrees, little longer than half of the trunk, slightly inflated at proximal third, with few short setae along the length and dense short setae around the mouth (Fig.
Legs slender (Fig.
Measurements of TIO2014DY34-5.001 in mm: trunk length from the anterior margin of the cephalon to the tip of 4th lateral processes 1.34; width across second lateral processes 0.68; proboscis length 0.76; abdomen length 0.25. First leg: coxa-1 0.17, coxa-2 0.34, coxa-3 0.18, femur 0.98, tibia-1 0.84, tibia-2 1.04, tarsus 0.06, propodus 0.51, main claw 0.25, auxiliary claw 0.12.
Trunk length (TL) and Trunk Width (TW) of other specimens: TIO2014DY34-5.002 (TL 1.29; TW 0.75), TIO2014DY34-5.003 (TL 1.03; TW 0.58), TIO2014DY34-5.004 (TL 0.99; TW 0.57), TIO2014DY34-5.005 (TL 0.41; TW 0.33).
The type location for E. straughani is Queensland, Australia (
Identifying the juvenile Endeis specimens was not an easy task, especially since there were no adult males collected, which would have provided information on ovigers and cement glands that are very important for determining species in this genus. Our juvenile specimens agreed generally with the descriptions given by
Almost nothing is known about the Endeis life cycle, other than an incomplete description of the life cycle of Endeis spinosa (Montagu, 1808) by Dogiel (1913, Taf. XIX, figs. 1-4 and 7-8), who described the protonymphon larva and several developmental stages in this species. According to the four distinct types of pycnogonid postembryonic development which were characterised by
Three specimens (TIO2014DY34-5.002, TIO2014DY34-5.003 and TIO2014DY34-5.004) have oviger buds (Fig.
In the absence of a complete life cycle to compare these specimens and based on the presence of four pairs of legs (4th pair still not completely developed) and also the presence of oviger buds in several of the specimens, they are probably at least 1 or 2 moults away from becoming adults (
Endeis straughani can be distinguished from other similar Endeis species in the same region (
Endeis viridis Pushkin, 1976, found in the Crozet Archipelago and Kerguelen Islands (
The specimens sustained some damage, such as unnaturally distorted tibiae and other kinds of damage during collecting, probably due to the pumping actions of the collecting apparatus (Fig.
Clark’s specimens (
Thanks so much to Dr. Xikun Song (Xiamen University) for help in identifying the hydroids. This work was supported by the National Youth Science Foundation (Grant No. 41606207), Scientific Research Foundation of Third Institute of Oceanography, MNR (Grant No. 2019025) and China Ocean Mineral Resources Research and Development Association Program (Grant No. DY-125-02-QY-06). Thanks to Dr. Bonnie Bain and several anonymous reviewers for improving this manuscript.