20/06/2014

Loài tôm gõ mõ mới ở Nha Trang Athanas manticolus

(biodivn.blogspot.com) Vào tháng Chín năm 2013, một mẫu vật duy nhất của Athanas được thu thập trên một vùng cát bán thuỷ triều liền kề với một rạn san hô gần bờ, san hô ra bãi biển Hòn Chồng, phía bắc thành phố Nha Trang, Việt Nam. Đây là mẫu vật con cái, sau đó được chụp ảnh khi còn sống, và ngâm etanol 70% làm mẫu vật. Kiểm tra hình thái của mẫu vật cho biết đây là một loài mới hoàn toàn chưa được mô tả. Do đó nhóm nghiên cứu mô tả loài mới cho khoa học với tên Athanas manticolus (Crustacea, Decapoda)Các mẫu chuẩn đầu tiên được gửi vào các bộ sưu tập của Bảo tàng Đại học Oxford Lịch sử Tự nhiên, Oxford, Vương quốc Anh (OUMNH.ZC). Tất cả các bản vẽ đã được thực hiện dưới kính hiển vi phẫu được trang bị một máy ảnh Lucida. Chiều dài mai (cl, trong mm) được đo dọc theo đường giữa lưng từ đầu của mai đến cuối. Công bố này được đăng tải trên tạp chí Zootaxa (3784 (5): 550–558) vào hồi tháng 4, 2014.

Athanas manticolus sp. nov., a new stomatopod-associated alpheid shrimp from Vietnam (Crustacea, Decapoda)
ZDENEK ĎURIŠ, ARTHUR ANKER
Abstract
A new species of the alpheid shrimp genus Athanas Leach, 1814 is described based on a single specimen, an ovigerous female from Nha Trang Bay, Vietnam. Athanas manticolus sp. nov. differs from all other species of Athanas by the presence of a small post-rostral tubercle, combined with a minutely toothed rostrum, reduced extra-corneal teeth, and the absence of infra-corneal and supra-corneal teeth. In addition, the new species is characterised by its unique colour pattern, particularly by the red chromatophores disposed in randomly oriented, short, narrow streaks. As its name suggests, A. manticolus sp. nov. is commensally associated with the burrows of the nannosquillid mantis shrimp Bigelowina phalangium (Fabricius, 1798).
Introduction
Most species of the alpheid shrimp genus Athanas Leach, 1814, recently re-diagnosed by Anker and Jeng (2007), are free-living under rocks or in coral rubble crevices. However, the genus also includes a number of symbiotic taxa associated with various marine invertebrates, e.g., stomatopods, mud shrimps, hermit crabs, fan clams, feather stars, brittle stars, and sea urchins (Crosnier & Forest 1966; Banner & Banner 1973; Froglia & Atkinson 1998; Anker et al.2001; Hayashi 2002; Marin et al.2005; Anker & Marin 2007).
In September 2013, a single specimen of Athanaswas collected on a subtidal sandy bottom adjacent to a near-shore coral reef off Hon Chong Beach, north of the city of Nha Trang, Vietnam. The specimen, an ovigerous female, was collected from a burrow with the aid of a suction (“yabby”) pump, together with its presumed stomatopod host (see below). Both the alpheid shrimp and the stomatopod were relaxed with clove oil and photographed alive before preservation in 70% ethanol. The morphological examination of the alpheid specimen revealed a unique combination of characters, suggesting that it belonged to a hitherto undescribed species of Athanas. This species is here described as new. The holotype is deposited in the collections of the Oxford University Museum of Natural History, Oxford, the United Kingdom (OUMNH.ZC), together with the stomatopod host. All drawings were made under a dissecting microscope equipped with a camera lucida. Carapace length (cl, in mm) was measured along the mid-dorsal line from the tip of the rostrum to the posterior margin of the carapace.
Athanas manticolus sp. nov.
Athanas manticolus sp. nov.appears to be most closely related to Athanas davieiAnker, 2011, presently known only from the northern Great Barrier Reef. The two species have many similarities, especially in the general shape of the frontal margin of the carapace, as well as in the shape and proportions of the chelipeds and walking legs (cf. Anker 2011). However, A. davieihas neither rostral teeth nor post-rostral tubercle (characteristic of A. manticolus sp. nov.), but on the other hand has spiniform setae on the propodus of the third and fourth pereiopods (absent in A. manticolus sp. nov.).
Athanas manticolus sp. nov. shares some characters, e.g., the absence of infra-corneal teeth, with Athanas iranicusAnker, Naderloo & Marin, 2010 from Iran; Athanas ahyongiAnker & Komai, 2010 from Madagascar and Japan; and Athanas shawnsmithiAnker, 2011 from the northern Great Barrier Reef. However, these three species differ from A. manticolus sp. nov.by the absence of rostral dentition and post-rostral tubercle, as well as by the differently shaped chelipeds (especially A. iranicusand A. shawnsmithi); A. iranicus also differs by the much longer second article of the antennular peduncle (cf. Anker & Komai 2010; Anker et al.2010; Anker 2011). None of the remaining species of Athanasis morphologically close to A. manticolus sp. nov.(cf. De Man 1911; Holthuis 1951; Chace 1955; Banner & Banner 1960, 1973, 1978; Chace 1988; Bruce 1990; Anker 2003; Anker & Jeng 2007; Anker & Ahyong 2007; Anker & Marin 2007).
The colour pattern of Athanas manticolus sp. nov.is unique within the Alpheidae (A. Anker, pers. obs.) in the arrangement of the red chromatophores on the carapace and abdomen, resembling unorganised reddish “hairs” (Fig. 6A–C). In most other species of Athanaswith an overall similar colour pattern (reddish body with a whitish or yellowish mediodorsal band), the chromatophores are grouped in smaller or larger dots, as inAthanas amazone Holthuis, 1951, A. japonicus (cf. Anker & Jeng 2007), A. shawnsmithi, A. daviei(cf. Anker 2011), or form a broad longitudinal band, as in A. ahyongi(cf. Anker & Komai 2010).
Athanas manticolus sp. nov.is the third species of Athanasreported to be associated with stomatopods, the other two being Athanas squillophilusHayashi, 2002 from Japan andA. amazonefrom the Mediterranean Sea, both morphologically very different from the new species (cf. Holthuis 1951; Froglia & Atkinson 1998; Hayashi 2002). 
In addition, another species of Athanas, presumably closely related to A. ahyongiAnker & Komai, 2010, is known to be associated with larger lysiosquillid stomatopods in the Philippines and Indonesia, based on underwater photographs (Kuiter & Debelius 2009: p. 159; A. Anker, pers. obs.). The burrowing host of the Madagascar specimens of A. ahyongi remains unknown, but based on the substrate and shape of the burrow entrance it may be either a stomatopod or a callianassid ghost shrimp (A. Anker, pers. obs.). Thus, associations between shrimps of the genus Athanasand burrowing stomatopods (Squillidae, Lysiosquillidae, Nannosquillidae) appear to be relatively common and likely more stomatopod-associated species will be found in the future.(biodivn.blogspot.com).
Phiên bản cuối cùng của bài báo có thể được tim thấy ở: 

0 nhận xét:

Post a Comment

Cảm ơn bạn đã để lại ý kiến, giúp chúng tôi cung cấp thông tin đầy đủ hơn nữa!