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Image of Macrodasys scleracrus Hummon 2011
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Macrodasys scleracrus Hummon 2011

Description

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Adult being described Lt 635 µm (others 394–800); LPh 290 µm (others 159–300) to PhJIn at U46 (others to PhJIn at U29–U47) (Fig. 10). Body medium in length as an adult, ventrally flattened, dorsally vaulted; head stepped, narrowing toward the mouth, with a narrow band of circumcephalic cilia at U02 and pestle organs in the step at U03; trunk of similar breadth throughout, narrowing quickly in the hind-gut region to the gradually delineated caudum of medium size. Widths at pestle organs /at U05 /PhJIn /anus /caudum, and locations along the length of the body are as follows: 45 /57 /54 /32 /13–10 µm at U03 /U05 /U46 /U91 /U92–U97, respectively. Glands inconspicuous. Adhesive tubes: TbA 7–9 per side (L 7–9 µm), in arcs that insert directly on the postoral body surface at U02–U04 and project from forward to obliquely outward; TbL 11, of similar size (L 12–18 µm), with 0 along the fore half and 2 along the rear half of the pharynx, 9 in the intestinal region, and 0 behind the anal aperture; TbV 14 per side, similar in size (L 7–8 µm), but giving the impression of linear pairs, all in the intestinal region, with 0 behind the anus; TbP 11–12 per side (L 9–12 µm) symmetrically around the caudum. Ciliation: Sensory hairs (L 10–20 µm) occur on either side of the mouth; a band of cilia surrounds the forehead (L 24–26 µm) at U02; other sensory hairs (L 8–16 µm) arise in three columns on either side of the body: lateral, dorsolateral, and dorsal, with about 30 per column. Ventral locomotor ciliature forms paired lateral bands that lie between the TbV series from the TbA back to the tip of the caudum, with additional cilia running in the medial space back to U73. Digestive tract: Mouth terminal, of medium width (16 µm diameter), surrounded by sharp tooth-like projections; buccal cavity expands from oral opening to base and is lightly cuticularized; pharynx is covered by circular muscles (visible under DIC) and has sub-basal pores at U36; intestine is broadest in front, narrowing to the rear and bending around the base of the caudal organ; anus is ventral at U91. Reproductive tract: Hermaphroditic; testes beginning just before the PhJIn, and extending as vasa deferentia back to the rear of the frontal organ, the termini not seen, though sperm can be seen in the vasa deferentia lateral to the frontal organ; ova develop from rear to front, with a large developing ovum (104 × 37 µm in size) above the fore-gut and ten smaller ovules to the rear; frontal organ asymmetrically pyriform (Fig. 10 a-c), its nozzle having a thick refractive cuticular cap, and lying in close contact with the largest developing ovum, and bearing sperm internally; caudal organ (Fig. 10 a) is of medium length, its fore half appearing glandular, and reducing in size proportionately with age (Fig. 10 c), its rear half having an internal canal and a spiral muscular covering, except for the rearmost sac; caudal organ barely overlaps the rear of the frontal organ, and not at all in older specimens. Ecology: Common in frequency of occurrence (30–60% of samples), scarce to prevalent in abundance (3% to greater than 30% of a sample (often a sub-[sdom], co-[cdom], or dominant[dom]);littoralin fine, medium sorted to very fine-very coarse, poorly sorted silicious to coralline sand, with coral debris, at mean low waterto extreme low water, 0–15 cm depth, occasionally occurring on a tombolo;sublittoralin fine, medium-well sorted to very fine-very coarse, very poorly sorted silicious to coralline sand, with coral debris at 1–15 m water depth, sometimes occurring in troughs and bars, between patches of healthy or unhealthy fringing reef, between coral platforms or in depressions in coral platforms.
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copyright
William D. Hummon
bibliographic citation
Hummon W (2011) Marine Gastrotricha of the Near East: 1. Fourteen new species of Macrodasyida and a redescription of Dactylopodola agadasys Hochberg, 2003 ZooKeys 94: 1–59
author
William D. Hummon
original
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Distribution

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Geographical distribution: MED SEA: EGYPT {Betash ’Agami [video], Marsa Matruh, Sidi Abd al-Rahman [video]}. RED SEA: EGYPT: {Abu Ramada 1, Abu Ramada 2 [2-videos], Abu Ramada 3, Sharm el-Arab Outside, Wadi ’Araba, Marsa Bareika N, ^Marsa Bareika W [dom] [video], Daghashland, Ein Sukhna, Giftun Island SE [video], Giftun Island SS [sdom], Main Beach Ras Mohamed NP [video], Mugawish [dom], Na’ama Bay N [dom], Na’ama Bay S [3-videos], Nabq [dom], Nabq S [sdom] [3-videos], Sharm el-Naga [cdom], Ras Nasrani, Nuweiba, Princess, Ras Qanti, Safaga, Ras Sudr [video], Tareef el-Reeh, ’Uyun Musa, West Gate Ras Mohamed NP [dom] [video]}; ISRAEL: {Coral Beach M3 [3-videos] & M4, Coral Beach S [video], North Beach [2-videos], Snuba DS} PACIFIC NE: HAWAIIAN ISLANDS: {Oahu: Hālona, Ka’a’awa [2-videos], Kaiona [sdom] [video], Penalu’u [video]}
license
cc-by-3.0
copyright
William D. Hummon
bibliographic citation
Hummon W (2011) Marine Gastrotricha of the Near East: 1. Fourteen new species of Macrodasyida and a redescription of Dactylopodola agadasys Hochberg, 2003 ZooKeys 94: 1–59
author
William D. Hummon
original
visit source
partner site
Zookeys