針(zhen)(zhen)烏賊，體較小胴部(bu)狹瘦(shou)，后端(duan)(duan)尖細，一般(ban)長(chang)(chang)約(yue)(yue)90mm，約(yue)(yue)為(wei)(wei)(wei)寬的(de)(de)2倍，鰭窄，頭部(bu)長(chang)(chang)約(yue)(yue)12mm。雌雄(xiong)異形顯著(zhu)，雄(xiong)性(xing)(xing)(xing)(xing)(xing)胴部(bu)瘦(shou)長(chang)(chang)呈圓(yuan)錐(zhui)形，腕(wan)(wan)(wan)(wan)(wan)(wan)序為(wei)(wei)(wei)2>4>1>3，其(qi)中(zhong)第(di)(di)2對腕(wan)(wan)(wan)(wan)(wan)(wan)約(yue)(yue)為(wei)(wei)(wei)其(qi)他(ta)各腕(wan)(wan)(wan)(wan)(wan)(wan)長(chang)(chang)度(du)的(de)(de)2倍以(yi)上，且(qie)極(ji)(ji)(ji)粗壯，頂端(duan)(duan)圓(yuan)，外側有紫(zi)色(se)環紋，腕(wan)(wan)(wan)(wan)(wan)(wan)下面2/3處(chu)吸(xi)盤(pan)(pan)為(wei)(wei)(wei)4行(xing)，余為(wei)(wei)(wei)2行(xing)；雌性(xing)(xing)(xing)(xing)(xing)胴部(bu)胱(guang)肥短(duan)，腕(wan)(wan)(wan)(wan)(wan)(wan)序為(wei)(wei)(wei)2>1>4>3，第(di)(di)2對和(he)第(di)(di)3對腕(wan)(wan)(wan)(wan)(wan)(wan)相似(si)，下面3/5處(chu)吸(xi)盤(pan)(pan)為(wei)(wei)(wei)4行(xing)，余為(wei)(wei)(wei)2行(xing)。兩性(xing)(xing)(xing)(xing)(xing)的(de)(de)第(di)(di)1對和(he)第(di)(di)3對腕(wan)(wan)(wan)(wan)(wan)(wan)吸(xi)盤(pan)(pan)為(wei)(wei)(wei)4行(xing)，頂端(duan)(duan)吸(xi)盤(pan)(pan)為(wei)(wei)(wei)2行(xing)；兩性(xing)(xing)(xing)(xing)(xing)的(de)(de)第(di)(di)4對腕(wan)(wan)(wan)(wan)(wan)(wan)吸(xi)盤(pan)(pan)均為(wei)(wei)(wei)4行(xing)，兩性(xing)(xing)(xing)(xing)(xing)的(de)(de)吸(xi)盤(pan)(pan)角質(zhi)環外緣，基本無齒，惟尖端(duan)(duan)小吸(xi)盤(pan)(pan)略具方形小齒。雄(xiong)性(xing)(xing)(xing)(xing)(xing)左側第(di)(di)4腕(wan)(wan)(wan)(wan)(wan)(wan)莖化，頂端(duan)(duan)吸(xi)盤(pan)(pan)極(ji)(ji)(ji)小。觸腕(wan)(wan)(wan)(wan)(wan)(wan)細長(chang)(chang) ，超過胴長(chang)(chang)，觸腕(wan)(wan)(wan)(wan)(wan)(wan)穗短(duan)小，約(yue)(yue)占全腕(wan)(wan)(wan)(wan)(wan)(wan)長(chang)(chang)度(du)的(de)(de)1/10，吸(xi)盤(pan)(pan)7-8行(xing)，大(da)小懸(xuan)殊(shu)，中(zhong)央(yang)4行(xing)最大(da)。生活時背部(bu)有極(ji)(ji)(ji)細的(de)(de)黃色(se)斑點。雄(xiong)性(xing)(xing)(xing)(xing)(xing)內殼長(chang)(chang)為(wei)(wei)(wei)寬的(de)(de)6倍；雌性(xing)(xing)(xing)(xing)(xing)內殼長(chang)(chang)為(wei)(wei)(wei)寬的(de)(de)4倍，角質(zhi)緣很窄，背面突起極(ji)(ji)(ji)細小，中(zhong)央(yang)有一條縱(zong)肋，末端(duan)(duan)骨針(zhen)(zhen)尖銳。