Extreme morphologies of mantis shrimp larvae

ABSTRACT Larvae of stomatopods (mantis shrimps) are generally categorized into four larval types: antizoea, pseudozoea (both representing early larval stages), alima and erichthus (the latter two representing later larval stages). These categories, however, do not reflect the existing morphological diversity of stomatopod larvae, which is largely unstudied. We describe here four previously unknown larval types with extreme morphologies. All specimens were found in the collections of the Zoological Museum, University of Copenhagen and were collected during the Danish Dana Expedition round the world 1928-30. These new larval types all represent erichthus-type larvae, especially differing in their shield morphologies. The shield morphology ranges from almost spherical to rather disc-like, with sometimes extremely elongated spines, but only a general systematic assignment of the larvae was possible. Further investigations of these larvae are crucial to understand their life habits and ecological impact, especially as stomatopod and other crustacean larvae might have a much more important position in the marine ecosystems than their corresponding adults.

摘要 口足类动物（mantis shrimps，螳螂虾）的幼体通常被划分为四种幼虫型：antizoea (antizoea)、pseudozoea (pseudozoea)（二者均代表早期幼体阶段）、alima (alima)以及erichthus (erichthus)（后二者代表晚期幼体阶段）。然而，这些分类并未反映出口足类幼体已被观测到的形态多样性，而该多样性在很大程度上尚未被研究。本研究描述了四种此前未被记录的、具有极端形态特征的幼虫型。所有标本均出自哥本哈根大学动物博物馆馆藏，采集自1928-1930年丹麦达纳号环球科考活动。这些新型幼虫均属于erichthus型幼虫，其形态差异主要体现在头胸甲(shield)的结构上。该类幼虫的头胸甲形态跨度极大，从近乎球形到类盘状均有分布，部分个体还带有极度修长的棘刺，但目前仅能对这些幼虫进行一般性的系统分类归属。对这些幼虫开展进一步研究，对于阐明其生活习性与生态影响至关重要——尤其是考虑到口足类及其他甲壳类幼体在海洋生态系统中所占据的地位，可能远高于其对应成体。