Two new species of Hypancistrus (Siluriformes: Loricariidae) from the rio Xingu, Amazon, Brazil Author Sousa, Leandro Melo de Universidade Federal do Pará, Laboratório de Ictiologia, Av. Cel. José PorfÍrio, São Sebastião, 68372 - 040, Altamira, PA, Brazil. (LMS) leandro. m. sousa @ gmail. com (corresponding author), (EBS) erildasousa. bio @ gmail. com. leandro.m.sousa@gmail.com Author Sousa, Erilda Barbosa de Universidade Federal do Pará, Laboratório de Ictiologia, Av. Cel. José PorfÍrio, São Sebastião, 68372 - 040, Altamira, PA, Brazil. (LMS) leandro. m. sousa @ gmail. com (corresponding author), (EBS) erildasousa. bio @ gmail. com. & Instituto Nacional de Pesquisas da Amazônia, Coordenação de Biodiversidade, Av. André Araújo, 69011 - 830, Manaus, AM, Brazil. (RRO) deoliveirarr @ gmail. com, (JZ) jzuanon leandro.m.sousa@gmail.com Author Ribeiro, Renildo de Oliveira Instituto Nacional de Pesquisas da Amazônia, Coordenação de Biodiversidade, Av. André Araújo, 69011 - 830, Manaus, AM, Brazil deoliveirarr@gmail.com Author Sabaj, Mark H. @ gmail. com, (LRPD) luciarpd 60 @ gmail. com. & Departament of Ichthyology, The Academy of Natural Sciences of Philadelphia, 1900 Benjamin Franklin Parkway, 19103 - 1195 Philadelphia PA, USA. (MHS) mhs 58 @ drexel. edu. luciarpd60@gmail.com Author Zuanon, Jansen Instituto Nacional de Pesquisas da Amazônia, Coordenação de Biodiversidade, Av. André Araújo, 69011 - 830, Manaus, AM, Brazil. (RRO) deoliveirarr @ gmail. com, (JZ) jzuanon & Senior Visiting Researcher at Universidade Santa CecÍlia (UNISANTA), Rua Oswaldo Cruz, 277, 11045 - 907 Santos, SP, Brazil. deoliveirarr@gmail.com Author Py-Daniel, Lúcia Rapp Instituto Nacional de Pesquisas da Amazônia, Coordenação de Biodiversidade, Av. André Araújo, 69011 - 830, Manaus, AM, Brazil. (RRO) deoliveirarr @ gmail. com, (JZ) jzuanon deoliveirarr@gmail.com text Neotropical Ichthyology 2025 2025-02-10 23 1 e 240080 e 240080 https://doi.org/10.1590/1982-0224-2024-0080 journal article 312354 10.1590/1982-0224-2024-0080 03b78c79-6ecb-440f-a7a6-263829e159fa 1982-0224 17161723 37E4D0DB-2310-4BE0-858E-2AC5D96FAA27

TABLE 2 | Morphometric and meristic data of Hypancistrus seideli. N = number of specimens; SD = standard deviation.

	Holotype	N	Range	Mean	SD
Standard length (mm)	98.1	111	29.3–116.5	–	–
Total length (mm)	131.5	108	40.9–150.2	–	–
Percentages of standard length
Predorsal length	42.7	111	37.8–48.2	41.7	2.1
Head length	36.9	111	32.1–41.7	35.9	1.8
Cleithral width	32.0	111	29.2–36.0	31.9	1.2
Thorax length	23.9	111	20.3–33.3	23.8	1.4
Pectoral-spine length	31.1	111	27.4–39.1	33.0	1.9
Abdominal length	24.2	111	18.8–28.1	23.7	1.4
Pelvic-spine length	26.2	111	23.2–33.8	27.5	2.1
Postanal length	32.1	111	15.7–38.6	32.8	2.7
Anal-fin spine length	14.2	111	10.8–29.8	15.5	2.0
Dorsal spine length	30.1	106	24.0–36.3	30.4	2.5
Dorsal-fin base length	30.5	111	25.2–33.1	28.9	1.4
Dorsal-adipose distance	16.1	111	8.4–34.0	14.1	2.4
Caudal penduncle depth	11.6	111	10.0–15.6	11.6	0.8
Adipose-spine length	9.0	111	5.7–14.3	9.1	1.1
Adipose-caudal length	6.4	111	2.0–12.6	6.9	2.3
Body depth at dorsal-fin origin	26.4	111	3.6–28.9	23.4	3.0
Body width at dorsal-fin origin	29.4	111	23.0–31.6	27.7	1.7
Body width at anal-fin origin	18.2	111	10.1–29.6	15.5	2.1
Post dorsal length	35.2	111	24.8–39.7	32.1	3.1
Percentages of head length
Orbital diameter	7.6	111	6.9–10.8	8.7	0.9
Snout length	13.8	111	4.3–15.3	13.2	1.1
Internares width	4.5	111	3.2–5.8	4.1	0.4
Interorbital width	11.5	111	8.8–12.7	10.5	0.9
Head depth	23.4	111	17.3–36.0	21.8	2.1
Dentary length	4.8	111	2.6–7.4	4.5	0.9
Premaxillary length	3.2	111	2.2–5.9	3.2	0.5
Head width	31.0	111	27.0–33.8	30.8	1.3
Eye-nare length	4.1	111	2.3–5.3	3.4	0.5
Interbranchial distance	20.2	111	14.9–24.9	18.9	2.1
Meristics	Holotype	N	Range	Mode
Teeth on premaxilla	10	111	5–18	11
Teeth on dentary	6	111	1–9	6
Lateral plates in middle series	25	111	19–25	23
Plates between anal and caudal	10	111	8–11	10
Plates between dorsal and adipose	4	111	4–5	4
Plates predorsal	4	111	3–5	4
Dorsal-fin branched rays	7	111	6–7	7
Pectoral-fin branched rays	6	111	5–6	6
Ventral-fin branched rays	5	111	5–6	5
Anal-fin branched rays	4	111	3–5	4
Caudal-fin branched rays	14	111	13–14	14