"barrel sponge" meaning in English

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  "forms": [
    {
      "form": "barrel sponges",
      "tags": [
        "plural"
      ]
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  "head_templates": [
    {
      "args": {},
      "expansion": "barrel sponge (plural barrel sponges)",
      "name": "en-noun"
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
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        {
          "kind": "other",
          "name": "English entries with incorrect language header",
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          "source": "w"
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          "source": "w"
        },
        {
          "kind": "lifeform",
          "langcode": "en",
          "name": "Sponges",
          "orig": "en:Sponges",
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        }
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      "examples": [
        {
          "ref": "2012, Caspar Henderson, The Book of Barely Imagined Beings, Granta Books, published 2013, page 29:",
          "text": "In making use of something as simple as a difference in water speed, barrel sponges are exploiting energy from currents and tides that ultimately derive from the gravitational pull exerted by the Moon and Sun.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A sponge of the genus Xestospongia, especially Xestospongia testudinaria."
      ],
      "id": "en-barrel_sponge-en-noun-PNL3JLib",
      "links": [
        [
          "sponge",
          "sponge"
        ]
      ]
    }
  ],
  "word": "barrel sponge"
}

{
  "forms": [
    {
      "form": "barrel sponges",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "barrel sponge (plural barrel sponges)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
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        "en:Sponges"
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        {
          "ref": "2012, Caspar Henderson, The Book of Barely Imagined Beings, Granta Books, published 2013, page 29:",
          "text": "In making use of something as simple as a difference in water speed, barrel sponges are exploiting energy from currents and tides that ultimately derive from the gravitational pull exerted by the Moon and Sun.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A sponge of the genus Xestospongia, especially Xestospongia testudinaria."
      ],
      "links": [
        [
          "sponge",
          "sponge"
        ]
      ]
    }
  ],
  "word": "barrel sponge"
}