Paschoal Lucas Rezende Penido, Nogueira Caio Santos, Zara Fernando José
Invertebrate Morphology Laboratory (IML), Department of Biology, School of Agricultural and Veterinary Studies (FCAV), São Paulo State University (UNESP), São Paulo 14884-900, Jaboticabal, Brazil.
Postgraduate Course in Biological Sciences (Zoology)/Ecology, Evolution and Biodiversity (EcoEvoBio), Biosciences Institute of Rio Claro, São Paulo State University (UNESP), São Paulo 13506-900, Rio Claro, Brazil.
Life (Basel). 2025 Jun 11;15(6):940. doi: 10.3390/life15060940.
The superfamily Alpheoidea comprises eight families: Alpheidae, Barbouriidae, Bythocarididae, Hippolytidae, Lysmatidae, Merguiidae, Ogyrididae and Thoridae. Alpheoids are characterized by possessing two pairs of chelate pereopods, a multiarticulate carpus on pereopod 2, and a narrow strip as the last article on maxilliped 2. However, during the inspection of the reproductive system (RS) of several alpheoids, we consistently observed the presence of ejaculatory bulbs (EBs) in vasa deferentia (VDs) of these shrimps. To investigate whether the presence of EBs in the RS is a conserved trait among Alpheoidea representatives, we analyzed as many species as possible along the Brazilian coast: Alpheidae-5 genera, 19 spp., Hippolytidae-2 genera, 2 spp., Lysmatidae-2 genera, 10 spp., Merguiidae-1 genus, 1 sp., Ogyrididae-1 genus, 2 spp., and Thoridae-1 genus, 1 sp. In addition, we examined representatives of the superfamilies Atyoidea (1 family, 2 genera, 2 spp.), Nematocarcinoidea (1 family, 1 genus, 2 spp.), Palaemonoidea (2 families, 4 genera, 4 spp.) and Processoidea (1 family, 2 genera, 2 spp.) to determine whether EB are present in these groups. Among the groups analyzed, except for the family Alpheidae, most species of alpheoids exhibit an expansion on the ventral portion of the VD in continuity with the lumen of the vas deferens, i.e., the EB. This structure increases the surface area of the VD, consequently increasing the quantity of the seminal material to be ejaculated onto the female. We did not observe the presence of EB in any other of the analyzed superfamilies, suggesting that this structure is exclusive in Alpheoidea. In conclusion, the presence of EB in VD appears to be an exclusive trait in Alpheoidea, being considered a well-preserved synapomorphic trait in this group, except in the family Alpheidae that do not harbor EB, representing a plesiomorphic condition within this superfamily.
鼓虾科、巴氏虾科、深海虾科、藻虾科、蝉虾科、长臂虾科、奥氏虾科和梭子虾科。鼓虾类的特征是具有两对螯状步足、第二步足上有一个多节的腕节以及第二小颚最后一节为狭窄的条带。然而，在检查几种鼓虾类的生殖系统时，我们始终观察到这些虾的输精管中存在射精球。为了研究生殖系统中射精球的存在是否是鼓虾总科代表物种中的一个保守特征，我们分析了巴西海岸尽可能多的物种：鼓虾科5属19种、藻虾科2属2种、蝉虾科2属10种、长臂虾科1属1种、奥氏虾科1属2种、梭子虾科1属1种。此外，我们还检查了异腕虾总科（1科2属2种）、线癌虾总科（1科1属2种）、长臂虾总科（2科4属4种）和原虾总科（1科2属2种）的代表物种，以确定这些类群中是否存在射精球。在所分析的类群中，除鼓虾科外，大多数鼓虾类物种的输精管腹侧部分与输精管腔相连处有扩张，即射精球。这种结构增加了输精管的表面积，从而增加了射精到雌虾上的精液量。我们在任何其他分析的总科中都未观察到射精球的存在，这表明这种结构在鼓虾总科中是独有的。总之，输精管中射精球的存在似乎是鼓虾总科独有的特征，被认为是该类群中保存良好的共源性状，但鼓虾科除外，鼓虾科没有射精球，代表了该总科内的一个祖征状态。
